Magnetite is a mineral that has been known about since ancient times. Magnetite is black and its crystals are usually octahedral prisms, but they can also be massive (having no distinct shape) or granular (a collection of tiny grains) Magnetite is very hard and has a dull metallic luster. Luster is a term that is used by mineralogists to describe the way that a mineral reflects light. When a mineral has a metallic luster it reflects light just like a piece of metal would. Magnetite can be found inside of volcanic bombs, which are blobs of lava that cool in midair and land on the ground solid pieces that are often a rounded shape; magnetite can also be found in meteorites. Magnetite is also known as lodestone.
One of the most interesting properties of magnetite is that it is a natural magnet. A natural magnet is a substance that exhibits magnetism and has not been magnetized artificially like many of the magnets that we use today. Unlike many of the magnets that we use to hold things to our refrigerators, magnetite is permanently magnetized. The magnetic properties of magnetite have been known since ancient times. In fact, magnetite was said to have been discovered by a Greek shepherd who was walking over a deposit of the mineral when the iron nails in the sole of his boot kept clinging to the rock beneath him. The ancient Chinese used the mineral to make early compasses and by the twelfth century the people of Europe were doing so as well. In Europe people made compasses by tying a needle-shaped piece of magnetite to a string and letting it hand like a plum bob. They called the mineral leading stone or lodestone.
In addition to its use as a compass needle, magnetite has served a great many uses. Magnetite is, like nearly every other mineral, a nice mineral to collect. I have even seen it in a rock and mineral kit in a toy shop. One of the most prominent uses for the mineral, however, is as an iron ore. Magnetite is about 70% iron by composition (compare that to other iron ores, such as taconite, which contains only about 17-35% iron) and therefore it can produce a great deal more iron than other ores of the same amount.
Magnetite is found in such places as the Italian island of Elba, Siberia, South Africa, and Sweden. Magnetite makes a fine addition to any collection. A word of warning, though. Do not let a specimen of magnetite get too close to your computer or credit cards!
Callaghanite is a very rare mineral that is composed of magnesium and copper. Callaghanite crystals are very small, usually less than a millimeter in size, and I have read that they are pseudo-octahedral or dipyramidal in shape. Unfortunately I am not well-learned in the subject of geometry so I do not know much of what those names mean. I cannot describe the exact shape of a callaghanite crystal based upon my own observation because I have never seen one under a great enough degree magnification. Callaghanite crystals are often found as incrustations (they form a crust on another rock or mineral) or as veins in rocks. Callaghanite crystals are azure-blue in color. By the way this color is not caused by impurities, callaghanite crystals are naturally blue. I have personally observed callaghanite specimens to sparkle a great deal when tilted and moved about under a light. Callaghanite is named for the American Mineralogist, Dr. Eugene Callaghan.
Because callaghanite is so rare there are no real uses for the mineral outside of collecting. It is not used as a gemstone because its crystals are far too small. In theory callaghanite could serve as a source of copper or magnesium, but it is far to rare to justify its mining for that purpose when there are other, more abundant sources of the metals available.
Being an extremely rare mineral callaghanite has few sources. Callaghanite can be found in Nevada, Oklahoma, Austria, and Italy.
Callaghanite is arguably the rarest mineral in my collection. I am quite thankful to have such an uncommon specimen and I hope that you can manage to acquire some as well!
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!
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!
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!
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.
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.
