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 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.
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.
.jpg)
.jpg)
.jpg)