Doing Some Moving

For anyone who has been wondering why I have made only one post during the last two months I now give my answer. I have been learning more and more about the Internet and have realized that I can do more with the settings, appearance, ect. of my site if I create my own website through another blog. I am sorry if any of you find this inconvenient and I hope that you will continue to enjoy my posts about rocks and minerals on the new site!
Sincerely,
Jake.
P.S. the new website in infantile right now, but you can visit it to see what I've been up to through the following address: http://explorerocksandminerals.com.

Heulandite: The Coffin Mineral

First off please allow me to appologize for the delay. I have been working on other projects a lot lately and haven't found the time to keep this blog up-dated. Also please forgive the brevity of this post. Again this is due to my lack of time.

The zeolite mineral heulandite was named for John Henry Heuland, an English mineral dealer. It is one of the most common zeolites--a family of silicate minerals. Heulandite is often coral-pink, but it can also be brown, white or red. It has either a pearly or vitreous luster and a Mohs hardness of 3.5 to 4.

Heulandite’s crystals are an oddity among minerals. If they are not altered by a natural processes then they will be shaped like the coffins from Western movies. These crystals can be distorted during their formation, which causes them to look differently.

Heulandite can be used for the myriad of purposes that many other zeolites serve. It has no use in the jewelry industry, but collectors like me love to collect it!

Heulandite is found in basalt like many of its fellow zeolites. Sources of the mineral include: India, Iceland, the Faroe Islands, Scotland, the Canadian province of Nova Scotia, and the American states of Washington, Idaho, Oregon, and New Jersey.

Lepidolite: the Purple Mica

Lepidolite is part of a group of minerals known as the micas, which I have written about before. I have chosen to cover lepidolite separately because it has a few unique properties, the most noticeable being its attractive color.

Ultimately, what sets lepidolite apart from the other micas is the presence of lithium in its chemical structure. In fact, one of the more common types of mica, muscovite, can be turned into lepidolite under the right conditions if lithium is present.

Lepidolite shares many traits with the other micas, but its individual chemical structure imparts a few properties that the others cannot claim. Like its cousins, lepidolite’s crystals are six-sided, very flat, and so soft that they are usually distorted. The crystals are often grouped as stacks and they’re commonly found as flakes. The thin crystals or flakes are flexible, a characteristic which is rare in the mineral kingdom. Lepidolite has a vitreous to pearly luster and a Mohs hardness of only 2.5 as do the other mica minerals.

Lepidolite’s first visible property that differs from lithium-free mica is its violet color, though it can take pale pink, or rarely gray or yellow. And it can be triboluminescent (when pressed it will emit little flashes of light in the dark.)

Lepidolite was once used as an ore of lithium, but the lithium content varies in lepidolite so people found other sources of the metal. Lepidolite is found chiefly within rock formations called “granite pegmatites” in places like: Madagascar, Sweden, the Brazilian state of Minas Gerias, and the American states of California, Connecticut, and Maine.

Sulfur: Mineral or Element?

Is sulfur a mineral or an element? Actually it's both. Sulfur is a type of mineral known as a native element. I have written an entire post devoted to this group of minerals, which can be accessed through the link above, so that you can learn about them.

Sulfur always displays a lemon-yellow color and for the most part is translucent. Its crystals belong to the orthorhombic crystal group and look like octahedrons made with isosceles triangles. Sulfur does not always take this form, however. It is often found as crusts or masses. It is very soft (only measuring at a 2 on the Mohs Scale) and it has a very low melting point. Sulfur is flammable, burning with a blue flame. (If you have any then you shouldn’t try this, though. Not only will you ruin a fine specimen, but you’ll also release a toxic gas!) Sulfur has a vitreous luster, but its masses are sometimes earthy. It has a white or yellow streak. Sulfur often exhibits a smell like rotten eggs, which can be a helpful trait when trying to identify it.

Sulfur has a long history of use. In ancient times it was used as a pigment and a tonic. Then, around the time of the Renaissance, it was employed to make gunpowder. Today sulfur is a very important substance in industry; I have read that the state of a nation’s industry can be guessed by its level of sulfur consumption. Most of the sulfur used in industry is converted into sulfuric acid, which is used to make pigments, explosives, sheet-metal, car batteries, and detergents. What isn’t made into sulfuric acid can be used in paper making, fungicides, and insecticides.

Sulfur is often found near volcanic steam-vents as crusts and masses. Good crystals can be uncovered in vugs (cavities) within limestone. Some sources of the mineral include: Sicily, Russia, Poland, Japan, Louisiana, Texas, and Wyoming’s Yellowstone National Park.

Limonite: Nautral Rust

Limonite a term which refers to an un-identified mixture of hydrated iron oxides and hydroxides--it is pretty much just naturally-occurring rust. Limonite is amorphous meaning that it has no crystal shape, and therefore it can’t really be considered a mineral, but I have never heard it classified as a rock. Perhaps it falls into the mineraloid category. Limonite is the color of rust and is found as massive, earthy lumps. For the most part is has an earthy or dull luster, which means that it does not reflect light. Limonite’s amorphous structure seems to be the only thing that separates it from goethite another mineral composed of iron oxides and hydroxides. Goethite forms fibrous crystals.
Limonite is famous for staining things with its yellow-brown color. In fact when you pick up a piece it will probably leave a dusty brown residue on your hands. Limonite is a coloring-agent in some soils and rocks, and it often colors agates and cherts. Sometimes this coloration occurs only on the surface forming a rust-colored crust, but it occasionally penetrates deeper. If you ever look for rocks in Lake Michigan or Lake Huron you will likely come across a great many chert pebbles that have been colored by limonite.
Limonite usually forms when other iron-bearing minerals (such as hematite) weather upon exposure. Since limonite is composed of hydrated iron oxide it will revert to hematite when it dries out. It also forms what is known as “bog ore”. Bog ore is limonite that forms as chunks below the water in marshlands and lakes.
Limonite was once used to make a kind of paint called “ochre”. It may serve as a minor ore of iron but I am not sure about that. It can be found theoretically wherever iron is present and seeing as iron is the fourth most plentiful element in the earth’s crust there are a great many potential sources.

Rock-Collection Labeling Made Easy

When I posted my piece on rock collecting for kids I had to leave this part out because if I hadn't the article would have been far too long. Since it is really a piece of my previous post it is still geered toward those who want to introduce the hobby to their kids, but please don't let that bother you. This post can be useful to anyone who is starting a rock collection and would like to find an easy way to label it.

Once your children identify their specimens they can label them. They can make labels by cutting sections of index cards and writing all of the information that they want on them. My labels usually include: the name of the specimen, the name of the specific site where I found it, the name of the county where the site is located, the nearest city to that site, and the state in which that city sits—in that order. For example, your child’s label might look something like this:
Jasper
Rockyland Ridge Mine
Custer County
Custer
South Dakota
What if the site where your kids found their rocks is a farm or even your driveway? You can label the sight after the name of the farm such as, “Maple Creek Dairy Farm,” or “Farmer John’s Sheep Farm,” or in the case of your driveway you can label it as “Smith Family Driveway,” or “Smith Site.”

If some of that information is missing then your kids can just omit it from the label. Some of my labels mention only the name of the mineral and the state where I found it. A few only mention the mineral's name. 


 

Rocks and Minerals for Kids: How to Get Started

Looking for a fun hobby to introduce your kids to? Have you ever considered rock collecting? Rock collecting (or “rockhounding,” as many in the hobby call it) is very popular these days. I started rock collecting when I was about five years old and I’m still doing it today.

The first thing you are going to need to start a rock collection is a few rocks. There are two ways that your kids can start their collections: they can find them themselves or they can buy them from places like museum gift shops.

Finding nice specimens in the field is not as complicated as you might think. If you have a gravel driveway then that can be your first place to look. Look for anything that stands out from the other pebbles in the driveway and save it as a specimen. Another great place to search is a farm field. Every time a field is plowed a lot of rocks are heaved up with the soil and will just sit in the field until someone finds them or they are plowed back under. Just ask a farmer if you and your children can spend a few hours searching through his field. In most cases he’ll be more than happy to let you take some of those pesky rocks away. You can also search for public accessible rock-collecting sites on the Internet.

Now that you’ve found some places to go rock hunting you can start planning your trip. Your children will each need something to carry their rocks home in. A cloth bag works really well for this purpose. If some of the specimens are fragile you can wrap them in toilet paper to protect them from harm. You may also want to take a pad of paper and a pen with you so that you can record the name of the site if you want to remember that later.

Once you have found a few nice specimens and brought them home they may need to be cleaned. If they have any dirt on them your kids can scrub that away with old toothbrushes and soapy water. A note of caution: it is a good idea to test the rocks by wetting the corner of the specimen before cleaning them. Some rocks will actually dissolve in water!

After the specimens are cleaned you can store them. I use plastic beading boxes with twenty compartments each to house my collection. This keeps the rocks and their labels together (I will talk more about the labels shortly) and allows you to store them in a compact space. These boxes cost less than five dollars a piece.

Now it’s time to identify the rocks. For this you will need a good rock and mineral identification book. These books explain how to identify minerals using their color, the streak test, the hardness test, and a lot of other techniques. Such books are a very good investment. You may want to consider purchasing a fossil identification book as well, since your kids may find a lot of fossils.