Wednesday, December 29, 2010

Vesuvianite: the Mineral of the Volcano

     Vesuvianite is named for Vesuvio, the Italian name of the volcano Mount Vesuvius, a place where the mineral can be found. Vesuvianite crystals are tetragon-shaped prisms, that is to say, they are prisms that look like rectangles that have trapezoidal end caps. Vesuvianite can also be found in a wide variety of colors such as, brown, amber-colored, red-brown, purple, violet, blue-green, yellow, yellow-green, green, colorless, white, or blue. In addition to its many colors vesuvianite also displays what is known as zoning. The term zoning is applied to a single crystal that exhibits different colors in different parts of the crystal. Some other minerals that exhibit zoning are rubies, and fluorite. Vesuvianite was once called idocrase, and the name is still used to some degree, so don’t let the two confuse you: vesuvianite and idocrase are actually the same mineral; it just has two names.
     Vesuvianite is used as a gemstone. It is rarely faceted as it is soft and people don’t like cut gems that display patches of different color. Vesuvianite is used to make cabochons and beads and its natural, uncut crystals are used to make jewelry as well. As a gemstone vesuvianite is occasionally called idocrase, especially when clear. Translucent green vesuvianite is sometimes called californite after the state in which it was discovered. In addition to its use as a gemstone vesuvianite is also sought by collectors, but it has no technological uses.
     One of the most notable historic sources of vesuvianite would be Mount Vesuvius in Italy, for which the mineral was named. Other sources include: Quebec, Canada; Brazil, Mexico, Peru, Sweden, Pakistan, Kenya, Namibia, Texas, Arkansas, and New Hampshire.
     Vesuvianite is a worthy addition to any collection, just be careful when collecting on volcanoes!

Monday, December 27, 2010

Okenite: God's Cotton Balls

     Okenite is a mineral that has very small crystals. Okenite crystals are usually acicular, that is, they look like needles, and are white, yellow-white, or blue-white in color. Okenite crystals are small, usually no more than a millimeter or two in length, and usually grow together as spherical aggregations of crystals that are often found in a radiating pattern. These spheres are made of okenite crystals that are packed closely together. Some crystals manage to protrude from this mass and give the little spheres a hairy appearance. Such aggregations of okenite are often called “cotton balls” because of their resemblance. Okenite can be found as single, blade-like crystals very rarely. Okenite crystals also exhibit a property that is quite rare in minerals: they are flexible. If you happen to have a specimen of okenite and would like to see the crystals’ flexibility then you can try bending one of the tiny crystals with something like a sewing pin, but DO NOT TOUCH THE SPECIMEN! The tiny okenite crystals can be crushed and stained easily by the human hand. In fact I do not recommend testing the elasticity of the okenite crystals at all, I am merely relaying the directions that I received from those who sold the okenite to me. I assume that these directions are safe enough, but I don’t want to risk damaging my fuzzy cotton balls. This brings up an important tip for collectors: it is a good idea to store okenite specimens in a way that they are safe from harm. I keep mine in a plastic case called a “perky box” so as to protect it from being mistakenly touched. I also glued it to a piece of Styrofoam that fits into the bottom of the case so that it won’t roll.
     Okenite is prized by collectors for its unique crystals and its rarity. Okenite is not used in jewelry because it is so soft, not to mention that its crystals are far to small to facet. Scientists are studying ways in which okenite might be used in industry, but so far nothing has been found.
Places where okenite can be found include: India, Germany, Denmark, Ireland, New Zealand, Israel, parts of the United States, and even Antarctica.
     Okenite is really unique among minerals. Its crystals are very small, and they are even flexible, I don’t know of any other minerals that are! Okenite can form whimsical cotton balls which look soft and inviting to touch, but please do not touch them!

Friday, December 24, 2010

Coal: Mineral Collectors Actually Want it in Our Stockings!

  
     Christmas Eve is upon us. It’s the night that Santa makes his worldwide run to reward good children with presents and bad ones with coal. Seeing as this rock has been given a spotlight during this time of year, I thought that it would be appropriate to write about it this evening.
Coal is a sedimentary rock that is formed by the compression of dead, rotted plant matter. Coal is somewhat of an example of a native element (that is, an element that is found in its pure, uncombined state in nature) A lump of coal contains nothing but the element carbon and a few impurities. Coal forms no crystals structure and is therefore amorphous (having no regular shape) Coal is soft and is black or blackish-brown in color.
     Coal is known to form by the compression of dead plants or other plant matter such as wood. In many cases coal is thought to form when plants and other plantlike materials die in a waterlogged area where their supply of oxygen is limited. The plants rot very slowly and are eventually converted into peat by natural compression. Peat is a brown, spongy mass or rotted plant matter. More pressure eventually turns the peat into lignite. Lignite, or “brown coal,” is a brownish black form of coal that is very soft. Lignite is about 30% carbon with a great deal of water making up the rest of it. More pressure eventually turns into bituminous coal, which is harder than lignite but is still soft, leaving a black smudge upon everything that it touches. Bituminous coal is about 60% carbon in composition. Further pressure turns bituminous coal into the highest grade of coal, which is called anthracite. Anthracite is the hardest type of coal and has a very shiny surface. Anthracite is the highest quality coal, being composed of 90% carbon. The process of coal formation as described above is said to, by some scientists; take millions of years to occur. I, however, do not believe this because wooden bridges have been found in America in which parts of the bridge had been turned into coal. For those who want to know the scheme by which coal is classified is known as codification.
     Coal has been used as a fuel for a very long time. Before the Industrial Revolution coal was used mainly by blacksmiths who used needed it to keep their forges hot enough to heat the metal that they worked with. Coal was also used to heat homes. Today some blacksmiths still use coal, but there are not as many blacksmiths around now as there used to be. Coal is not burned in people’s fireplaces anymore because it of its smoky scent and the fact the prolonged exposure to coal smoke (which contains potent gasses such as carbon dioxide, carbon monoxide, and sulfur dioxide) can lead to health risks. The primary use of coal today is as a fuel in power plants. Since coal is burned to make electricity one can say that it is still used to heat home, albeit indirectly. Coal is also burned to make coke, a substance which is used in metallurgy. Coal extracts are also used to make dyes, nylon, animal feedstock, and mint candies.
     Coal is found in large deposits all over the world. In fact, there are very few places on earth that do not contain at least some coal. I have found a good deal of  coal in the area where I live that was not mined, but was in its natural state.
     The notion that Santa Claus punishes bad kids with a lump of coal has given the rock a poor reputation. In reality coal is a magnificent rock. Its sable color and broad usefulness make it a rock that I am glad to have. So, I wish a merry Christmas to all who read this, and if you are a blacksmith or a mineral collector I hope that you get some coal in your stocking!

Wednesday, December 22, 2010

Ulexite: TV Rock


     Ulexite is a colorless borate mineral that was named for the German chemist George L. Ulex. The term borate mineral refers to any mineral that contains the elements boron and oxygen in its chemical makeup. Ulexite crystals are colorless and have a vitreous luster (that means that their surfaces reflect light in the same way that glass does) Single ulexite crystals are rare; ulexite crystals are usually found growing together in nodular, rounded, or lenticular aggregations (I.e. they look like knobs, spheres, or lenses) of fibrous crystals. These aggregations can be white or cloudy, are translucent, and have a silky luster.
     Ulexite has a rather strange property in which its fibers transmit images somewhat like a television screen. If you place a piece of ulexite on top of a page of text the ulexite crystals somehow transmit the image so that it looks like the letters are sitting on top of the mineral! It will do this with any image, even three-dimensional objects. I do thing that the ulexite specimen must have its top and bottom faces polished to do this, but I do not know. Because ulexite can transfer images like this it is often called “television rock” or “TV rock.”
I know of only one use for ulexite and that is as a collectible mineral.
     Ulexite is usually found in dry places where there is a good deal of boron present. Some of the usual places where ulexite is found would be dry lakes, and marshes. Ulexite is an evaporate mineral, which means that it crystallizes as a result of evaporation, so it makes sense that it is found in dry places (where water evaporates rather quickly) Some of the best places to find Ulexite are: Nevada, California (a place that is famous for its borate minerals), Chile, and Canada’s Maritime Provinces.
     I find ulexite very interesting because it can do something that few other minerals can: namely to transmit images like a TV set. In the Bible it says that God created everyone to be different according to the tasks that He has assigned us (Check out 1Corinthians chapter 12) It appears that the same is true with minerals.

Monday, December 20, 2010

Sphalerite, I Zinc it's Great!

  
      Sphalerite is a sulfide mineral that is also rich in the metal zinc. When a mineral is called a sulfide that means that one of the major components in its chemical makeup is sulfur. Sphalerite is made up of only two elements: sulfur and zinc. Sphalerite crystals are usually tetrahedral prisms (prisms that have four faces) but can also be octahedral (having eight faces) or dodecahedral (having twelve faces) and the faces of its prisms are usually rounded. Sphalerite can be golden brown, yellow, reddish brown, yellow-orange, red, brown, green, black, or rarely colorless or white in color. Sphalerite is also known by many nicknames. Some of my favorites are: zinc blende, honey zinc, black jack, and ruby jack. Sphalerite also displays what is called trboluminescence. When a mineral is triboluminescent it will give off flashes of orange light when it is scratched with a metal object. In addition to emitting orange flashes of light when scratched, sphalerite also smells like rotten eggs! Sphalerite’s name is derived from the Greek word sphaleros, which means “treacherous” or “deceitful.” It was given this name because it is often confused with the mineral galena, another sulfide mineral.
     Sphalerite’s main use today is as an ore of the metal zinc. Zinc is the fourth most widely used metal today, surpassed in use only by iron, copper, and aluminum. Zinc is used to protect steel from rusting by coating it in a process called galvanizing, and is alloyed with copper to make the metal brass. Zinc has also been used to make the core of the American penny since the early 1980s. Sphalerite has few other uses beside that of an ore stone, but it is sought by collectors and occasionally cut as a gemstone. Sphalerite is far to soft to be used as a wearable gemstone and is really only cut for gem collectors.
     One of the best locations that I know of where sphalerite can be found is certain deposits in Tennessee. Sphalerite is found in many places throughout the central United States including: Illinois, Wisconsin, Kentucky, Kansas, Oklahoma, and Missouri. Other American locales include Idaho, Alaska, New Jersey, Colorado, and Utah. Sphalerite is also found outside the United States in such places as: Bulgaria, Austria, Italy, France, Spain, Germany, and China.
     Sphalerite is important both as a collectible mineral and as a source of a very useful metal.

Saturday, December 18, 2010

Turquoise: the Mineral That Captures the Color of the Sky


     Turquoise is a blue mineral that is found in dry regions of the earth. Turquoise is almost always a shade of greenish-blue (even the name turquoise has become synonymous with this color) but I have heard rumors of a white turquoise, but I don’t know if it really exists. Turquoise can also have black lines running throughout it in uneven patterns. When this happens the stone is called “spider web turquoise.” The shades displayed in turquoise can vary depending on its content of iron or copper (the more iron present the greener the stone will be and the more copper present the bluer the turquoise) Large crystals of turquoise have never been found; instead turquoise is usually found in massive amorphous lumps made up of thousands of tiny grains. Turquoise is light and very fragile and breaks with a conchoidal fracture. When a mineral is said to have a conchoidal fracture it breaks in a pattern that resembles a conch shell. Most minerals that break with this kind of fracture can be made into arrowheads and knives, but turquoise is too soft for this kind of use. Turquoise is also very light.
     Turquoise has been used as a decorative stone since ancient times and is still used for such a purpose today. Decorative stones are used to make jewelry and other decoration, but are not valued as highly as gemstones. Turquoise has been a popular decorative stone for many years. The Aztecs, Navajos, and Persians used it to make jewelry and carvings and the stone was used in Europe as soon as it was brought there via Turkey (the name for turquoise was actually derived from the word Turkish) Today turquoise cabochons make popular settings for silver rings (especially in the western United States where spider web turquoise is very popular) In most places people consider bluer turquoise more desirable than greener pieces.
     Turquoise is found mainly in dry environments such as deserts, therefore most of its sources are arid countries. The oldest known source of turquoise is Iran where turquoise has been mined for over three thousand years. The Aztecs mined their turquoise in the southwestern United States, which is where most of the world’s turquoise comes from today. Turquoise is also found in Mexico, Australia, Chile, and Turkmenistan. Though not a dry area, turquoise can also be found in Cornwall, England.
     Turquoise, thought not as valuable as certain gemstones, is still a beautiful mineral. I like to think that the Lord decided upon its color so as to remind us of the sky on cloudy days!

Thursday, December 16, 2010

Galena, Beautifal, but Dangerous


     Galena is a mineral that is composed of sulfur and lead. It is silver or gray-colored and is very shiny. It is said to have a metallic luster, which means that its surface shines in the light like metal. Galena crystals are usually cubic but they can also be shaped as a combination between a cube and an octahedron. Fibrous galena crystals exist, but they are very rare. Galena crystals have perfect cleavage. Cleavage, in the mineral world, is a term that is used to describe the way crystals break (or cleave) along certain planes. Galena crystals cleave in three directions which leaves the broken surface smooth and flat. When galena crystals break they usually have a stepped surface, though the designation of perfect cleavage still applies because they surfaces of these steps are still smooth, the mineral is merely breaking along many small planes. Due to the fact that one of its two main components is lead galena is very heavy and has a high specific gravity (read more about specific gravity in Barite: the Mineral That’s Used to Make Milkshakes, another post that I made at an earlier date, which you can find in my blog archive under December) Galena’s high lead content brings up an important point: galena is a poisonous material. Lead is a toxic metal and many of its compounds are poisonous as well, galena is no exception! As a rule you should always wash your hands after handling galena.
     Galena is used primarily as an ore of lead. Lead can be extracted from galena quite easily. In fact, ancient Greek and Roman writers described how rocky outcrops of galena could be reduced to lead during wildfires. Lead was once used to make many things, especially plumbing solder and pipes (the word plumber comes from the Latin word for lead, plumbum) However, it is used less frequently today because we have come to realize that it is a dangerous material. Nevertheless, lead is still used to make car batteries (which are also called “storage batteries”) ammunition, and solder designed for uses other than plumbing. Lead is also used to make stained-glass windows. Galena can be a source of silver because it is often found in the mineral as an impurity.
     Galena is found in Italy, France, Austria, and Germany. The ancient Romans mined the mineral in Spain and England. It is also found in Peru, Bolivia, and Mexico. The United States is also a good source of the mineral. There are 36 U.S. states that have significant galena deposits. Missouri is one of the best that I personally know of.
     Galena certainly makes a nice addition to any collection, but be warned: it is poisonous. You should always take special care when handling it!

Tuesday, December 14, 2010

Tektites, the Mysterious Little Rocks


     Tektites are a variety of what is called “natural glass.” Natural glass refers to a glassy substance that is made when rocks melt naturally. Obsidian is a famous variety of natural glass and looks very similar to some tektites (especially when polished) but tektites can be distinguished by the fact that they do not contain the microscopic crystals that obsidian does. Tektites are usually green, dark brown, or black in color and are found as little nodules that are usually less than four inches in diameter. Tektites are usually found as spheres, tear-drop shapes, lenses, dumbbell-shapes, discs, and ellipses. Tektites were first discovered in the Moldau River in the former Czechoslovakia and were named moldavites. Today the term moldavite refers to a green variety of tektite found only in that area. The varieties of tektites are named from the places in which they are found. For example: a tektite found in Australia is called australite.
     For a long time scientists did not understand the tektite’s origin. For a long time it was suggested that tektites were formed when meteorites passed through the earth’s atmosphere. When a meteorite enters the earth’s atmosphere it is subjected to a great deal of heat as it passes along (this is why they look like “shooting stars” at night) Tektites were once thought to be leftover blobs that fell off of a meteorite’s molten surface. Tektites were once thought to come from the moon as well. Today it is thought that when a meteorite strikes the earth the intense heat caused by the impact will melt the sand around the meteorite, thus making tektites out of rocks from the earth and not for the meteorite itself. We may never know exactly how tektites are formed, but most theories have something to do with space.
Tektites have few uses outside of the rock and mineral collection. I would assume that they are used in science, but I do not know exactly what they could be used for. Tektites (especially moldavites) are also cut as gemstones occasionally.
     Since tektites are thought to be formed by the action of meteorites slamming into the earth’s surface they could be found, in theory, anywhere on earth where a meteorite has struck. Places where large deposits of tektites can be found include: Russia, the Australian state of Tasmania, Australia, southern China, the Ivory Coast, and the Czech Republic. Tektites have also been found in Thailand.
     Tektites are an amazing and mysterious part of God’s creation. We may never know how they are formed or where they come from, but I don’t think that that will stop people from collecting them any time soon!

Friday, December 10, 2010

Halite: Salt of the Earth


     Halite (which is also called “rock salt”) is chemically the same as common table salt. What differentiates halite from the stuff in our salt shakers is its form and color. Halite grows as large, cubic crystals that are often found growing together as large conglomerate masses. In addition to the cubic shape that the halite crystals usually display they have also been found as octahedrons, and fibers. Halite has also been found as encrustations, stalactites, and hopper crystals. A hopper crystal occurs when a crystals edge grows faster than its face. This results in a crystal that has stepped depressions all over its face. Halite most commonly smoky gray in color, but when absolutely pure it can be white or clear. Impurities can cause it to be red, pink, blue, purple, yellow, orange, and green. Most of these colors are usually very pale, but purple and blue can show very strongly. Like all salt, halite dissolves in water, so if you have any in your collection don’t let it get too wet!
     When thinking about what possible uses there could be for the mineral halite, remember that it is salt and is used in every way that one would use salt. Halite is, of course, used to flavor food and was once used to preserve meats. Halite is also a major source of the salt that places with colder climates use to keep their roads from icing. Halite is also used as a source of the metal sodium which is used to make lye (sodium hydroxide.) It is also used to purify water and in modern food processing.
I have personally seen halite do some interesting things. I once grew a stalactite of salt that was hollow and had angular sides. It was about two and one half inches long. Also, in Acadia National Park, Maine I found a puddle that appeared to be frozen, but when I touched it I found that the white covering atop it was actually crystallized salt!
     Halite is found in many places on the earth, the seashore being the most notable. It is an evaporate (a mineral that crystallizes as the result of evaporation.) Fine specimens can be found in California. Large halite deposits can be found underground as well. There are famous salt mines in Poland and beneath Detroit. There are also mines in New York state. The Great Salt Lake in Utah is a good source of evaporate salt as is the Dead Sea in Israel.
     Halite’s name can be a little misleading, but I don’t mind. It is important to science, the food industry, road safety, and many other such things. Who would have thought that salt can be so important?

Wednesday, December 8, 2010

Cavansite: a Useless Mineral?


     Cavansite is a rare mineral that is found in only a few places on the Earth. Cavansite is usually found in vesicles (gas bubbles) or cracks in basalt and andesite. Cavansite is usually found as tiny, orthorhombic, blue crystals. So far there have been no examples found in which cavansite that displays any color other than blue, but cavansite does exhibit different shades of blue varying from greenish blue to deep blue and a color that is known as electric blue. Cavansite crystals are very small and are usually found as clusters or aggregations. These clusters can be radiating spheres, tufts, or rosettes, which are shaped like roses. Cavansite is named for the three most prominent elements that make up its chemical formula: CAlcium, VANadium, and SIlicon.
Like many discoveries, cavansite was discovered by amateur collectors. In the fall of the year 1960 a couple was driving through Owyhee State Park in Oregon. They caught sight of a blue mineral in a rock face that had been exposed by a recent road cut. They and another couple collected some samples of the mineral and sent it to Dr. Paul Desautels of the Smithsonian National Museum who said that their discovery was probably a new, undiscovered, mineral. Three years later a man named John Cowels found some the same mineral and sent it to Dr. Lloyd Staples to have it identified. Dr. Staples determined it to be a new mineral. Next time you are tempted to think that you cannot make a contribution to science just because you are not a professional remember this story!
     The last mineral that I wrote about was barite, which is used for a great deal of things. Cavansite contrasts barite fairly well because it has no technological uses. Cavansite crystals are also too small to use as jewelry so the only market in which cavansite sells is the collector’s market. Perhaps the Lord created cavansite simply to add some artwork to the Earth’s rocky infrastructure.
     There is only one source throughout the world in which cavansite can be mined in large enough quantities for collectors and that is in India. My specimen was collected in the vicinity of the Wagholi village in India. It is also found in very small amounts in Oregon, Brazil, and New Zealand’s North Island.
     If there is one thing that this blog has taught us it is that just because something may not be prestigious does not mean that it is useless. Cavansite has small crystals, is too rare for any technological use, and is not used to make jewelry, yet it is certainly not useless. Cavansite is prized by collectors and it is a beautiful mineral. This article can also teach us that an amateur’s discovery may be an important one too!

Monday, December 6, 2010

Barite, the Mineral That's Used to Make Milkshakes

    
     Barite is a mineral that is often found near hot springs, in lime stones, and in lead and silver mines. Barium crystals are usually orthorhombic, that is to say they are like little peaked roofs with ends that face inward, and they are usually white, gray, colorless, yellow, gold, brown, red, and blue. Barite is also found in many other forms. Barite forms a “cock’s comb” when its crystals are flat and rounded like a comb on a chicken’s head. When barite is found in form that resembles a flower it is called a “barite rose” or “desert rose.” Desert roses usually form in desert terrains (hence the name desert rose) this occurs when water containing dissolved barite evaporates quickly. Barite also has a very high specific gravity (that means it feels heavy for its size. Drawing from what I remember of my high school chemistry classes, I believe that the reason that barite is so heavy is that it contains the element barium, which is heaver than iron. When an element is heavy or dense, its compounds usually are as well, when compared to compounds containing other, less dense, elements.
     Barite is a very useful mineral. Barite is so useful, in fact, that you have probably come into contact with the mineral on many occasions. One of the key uses of the mineral is to make what is called “drilling mud.” Drilling mud is a compound that is used to lubricate the drill heads used in the oil-drilling industry. Barite is used to make a high-refraction glass called leaded glass or leaded crystal. Tiny barite chips are also added to paints, enamels, plastics, and papers to make the glossy. If you have ever read a magazine with a really shiny cover, chances are that barite was used to give it its sheen. It is also possible that you have ingested barite before. If, like myself, you have ever had an x-ray of your gastrointestinal tract taken, and were given the “magic juice” or “barium milkshake” than you have drank barite. Barium has the ability to absorb x rays and gamma rays, so it will stop them from passing through body tissue. When you drink a “milkshake” that contains barium the mineral will be present in your digestive tract and stop x-rays from passing through it, allowing the picture to be taken. Barite is also added to concrete to make “heavy cement,” which is used to store radioactive waste. Barite is also a source of the metal barium, which is used in scientific research.
     Barite is found in such places as: England, Romania, Italy, Texas, China, Mexico, British Columbia, South Africa, and Australia. Not only are fine crystals mined as choice specimens, but barites of less desirable shape are mined in large quantities for such industrial uses as those mentioned above.
     Barite, arguably the most useful mineral that I have written about yet, is certainly an important mineral in our lives today. It is a very desirable mineral for collectors, and for milkshake makers. (I’m joking about that last one!)

Thursday, December 2, 2010

Molybdenite, What a Softy!

 
     Molybdenite is a mineral that is shiny, and silvery-gray in color. It’s color is actually very similar to that of lead. Molybdenite crystals are hexagonal and are very thin, far thinner than paper, but they are usually found bunched together to make larger pieces in the same manner as the mineral group mica. And, just like mica, these thin sheets can flake apart with only a little effort. As the headline suggests molybdenite specimens are very soft. So soft that they bend easily so their hexagonal shape is often destroyed and they are often found in an amorphous state (which means that they have no regular shape, kind of like gold nuggets) In addition to being subject to distortion molybdenite can also wear very easily. In fact it will leave a silvery-gray smudge on almost anything that touches it so it’s probably best not to let molybdenite touch any expensive clothing! Molybdenite’s name comes from the Greek word molybdos, which means lead. This is because when the ancient Greeks discovered molybdenite they thought that they had found some new and strange form of lead.
     Molybdenite is the chief ore of the metal molybdenum, which is used to make certain steel alloys such as tool-steels. For some time now, I have wanted to attempt to extract pure molybdenum from a small piece of molybdenite via either chemical reaction or a process known as electrolysis, but have not yet made this attempt. I do not recommend that any readers do so either until they have taken all necessary safety precautions and have researched the topic thoroughly.
     Molybdenite is found in many places including: Sweden, Norway, Chile, Korea, England, the western United States, Michigan’s Upper Peninsula, and Queensland, Australia.
     Molybdenite is, in my opinion, a visually appealing mineral. After all, there are very few minerals that I know of that look like pieces of metal! I am very thankful to own a piece of this mineral, even if it is a bit soft.