Friday, April 29, 2011

Crocoite: The...Crocodile Mineral?


     With a name like crocoite it does seem like the mineral must have been named after a carnivorous Egyptian reptile. Actually crocoite’s name comes from the Greek word krokos, which means “saffron.” It was given this name because crocoite has a saffron-colored streak. While crocoite’s streak may be saffron-colored, its crystals are usually reddish-orange in color, but orange, red, and yellowish-orange varieties are also known to exist. Crocoite’s crystals are rectangular prisms that usually grow as long, skinny needles. Crocoite is transparent or translucent and its luster is adamantine (which means that it reflects light like a diamond.) However, it does not serve as a gemstone because it is too soft (not to mention the fact that this adamantine luster can fade when crocoite is exposed to the sunlight. In addition to being soft, crocoite’s crystals are sometimes hollow.
     One of the most historic sources of crocoite is the Australian island of Tasmania where crocoite has been mined for more than 100 years. Other sources include: England, Germany, Russia, France, Austria, Scotland, South Africa, Chile, the Canadian province of Quebec, and the American states of Arizona and California. Crocoite once served as an ore of chromium and was used to make paint. Today it is still used to make a type of specialty paint called “chrome yellow,” but it has been replaced as a chromium ore by a mineral called chromite.
     Crocoite is, in my opinion, a very beautiful mineral. Not only is its color very distinguished crocoite has crystals of an uncommon shape. It’s certainly no ordinary mineral!

Friday, April 22, 2011

Staurolite: An Appropriate Mineral for Good Friday (Part Two)

     Staurolite is certainly interesting as a mineral, but it can represent something far more important. Staurolite can serve as a reminder of what our Savior endured on our behalf. If you already know the Savior now would be a good time to thank Him for suffering death on a cross for you. If you do not know the Savior there is no better time than now to do so. No human is perfect and God requires that only those who are perfect may go to Heaven when thy die. However, Jesus, God’s one and only Son, died to pay the penalty of sin, even though He had never sinned. Now absolutely anyone can be made perfect by the power of Jesus. All you have to do is ask Him to forgive your sins and come into your heart. You can say something like this to him: “Dear God, I know that I am a sinner and deserve to be punished. I believe that Jesus is your Son and that He can heal me. I am ready to turn away from my sins and I believe that Jesus is your son. I ask him to come into my heart. Thank you, Jesus, for coming into my heart like you promised. Amen.” If you have prayed that prayer and meant it than your sins are forgiven past, present, and future and you are now part of God’s family. You will go to Heaven when you die and you have God’s Holy Spirit living inside of you at this very moment and He will never leave. That is a greater treasure than all of the minerals in the world!

Staurolite: An Appropriate Mineral for Good Friday (Part One)


     Staurolite crystals are hexagonal prisms that can be reddish-brown, yellow-brown, brown-black, or rarely blue in color. It is not altogether uncommon to find staurolite crystals on a matrix. In the mineralogical world the term matrix refers to a piece of rock or dirt that a crystal is connected to. Staurolite crystals are famous for their twinning properties as well. Staurolite crystals have been known to intersect each other at angles of 60 and even 90 degrees, thereby forming cross-shaped crystal twins. This is actually where staurolite gets its name from. The name “staurolite” is composed of the Greek words stauros (which means “cross”) and lithos (which means “stone”) so staurolite’s name actually means “cross stone.” In addition to its scientific name, staurolite twins are known by a number of nicknames, the most famous of which is “fairy cross.” Other nicknames include: “cross stone” “faith cross” and “angel cross.” appropriate
     Staurolite has been used as a cross symbol since Medieval times. In those days staurolite twins were collected and used to represent Christ’s cross both on a matrix and free of one. Those that were free of a matrix were used to make pendants. Today staurolite crosses are used to make pendants and broaches, and small ones are used to make earrings. Finely ground staurolite can also be used as an abrasive in sand-blasters when a medium that is harder than quartz is required. Blue staurolite can also be used to make pigments.
     Staurolite is found all over the world, but collectible specimens are found in only a few places. Such places include: Russia, Ukraine, Japan, China, Spain, Turkey, and the Appalachian Mountains of North America.

Thursday, April 14, 2011

Sharing Your Collection With Others: One of the Best Uses For a Rock Collection

     Yesterday I had the opportunity to share my rock collection with others. I always love to show the minerals I’ve collected to other people and hopefully foster an interest concerning the subject in some of them.
     I brought my collection to a home schooling co-op and talked about it as well as some interesting facts about minerals like: the sources of a mineral’s color, the meanings behind mineral names, and much more. I also shared a few tips about mineral identification like the streak test and the Mohs’ scale. After my little talk ended everyone simply looked at my collection a bit and I answered a few questions. Then it was my turn to have a look at their collections and I must say that the students had some pretty nice specimens! I did my best to identify some of the minerals that they found and for the most part I could tell what sort of minerals they had, but there were some samples that I simply could not identify. Everything must have gone well because I had one student thank me for coming three times! What an honor!
     To all of the collectors out there I say that if you ever get a chance to show your minerals to other people you should do it. It provides a chance to get other people interested in the hobby and best of all it can offer us an opportunity to thank the Lord for blessing us with our fine minerals by using them to bless others!

Monday, April 11, 2011

Iolite, Now There's a Mineral of a Different Color!


     I think that it’s safe to say that iolite could be the face of pleochroic minerals. Pleochroic minerals are minerals that exhibit different colors when viewed from different angles. Iolite appears to be violet-blue when viewed down the length of its crystals, but colorless when looked at from the side of its crystals. This amazing change of color makes iolite one of my favorite minerals. Unfortunately my piece doesn’t display this pleochroism. Perhaps the fact that it’s too compact to allow a lot of light to pass through it has something to do with that.
     Iolite is said to have orthorhombic crystals, but I’ve never seen a picture-perfect iolite crystal, so I can’t describe what it looks like except for the fact that it’s prismatic and has flat faces. Iolite is also found as compact masses. I have seen transparent and translucent iolite, but I’m not sure if it can be opaque. Iolite has a vitreous luster like quartz and shares quartz’s Mohs scale hardness of 7. Because it is dichroic (dichroic means that it is pleochroic with two different colors) iolite is also called dichroite. Iolite is also known by the names cordierite and ‘water sapphire.’ Iolite’s only commercial use outside of collecting is as a gemstone.
     You can find iolite in places like: India, Myanmar, Sri Lanka, Madagascar, Norway, Finland, Germany, and Wyoming.
     Iolite is one of my favorite minerals simply because it has some of the most remarkable pleochroism that I’ve ever seen. It’s a really cool mineral and I’m glad that God saw it fit for me to have a sample of it!

Tuesday, April 5, 2011

Native Elements: Building Blocks in Pure Form

     Native elements are rare among minerals. Of the 4,600 or so different mineral types out there only about twenty of them are native elements. What is a native element? A "native element" is simply a chemical element (a member of the periodic table) that can be found uncombined in nature. The elements on the periodic table usually link up with other elements to form compounds and to get samples of these elements people usually have to separate them from their compounds (this is actually what is happening when people extract metals from their ores.) However, some elements can be found not combined with any others. These are called “native elements” and they are considered to be minerals.
     The elements gold, silver, copper, lead, platinum, palladium, iridium, osmium, iron, mercury, tantalum, tin, antimony, arsenic, bismuth, selenium, tellurium, carbon, and sulfur have all been found as native elements. They have crystal structures like other minerals, but I don’t plan to discuss their appearance. Some of these elements can also be found as native alloys (an alloy is a mixture of metal.) Native iron, for example, quite often contains nickel. The elements osmium and iridium are never found pure in nature, but always as natural alloys. Native iron is seldom found on earth; it’s usually found in meteorites. People in at least three countries have reported finding native zinc, but no one has proven it yet.
     Native elements are rare among minerals. In my opinion they are some of the most interesting minerals on earth. For this reason I am glad that God saw it fit to leave some of His building blocks in pure form for people to find!