rocks

Most of the specimens featured here, unless they are fossils

Uvarovite

Lots of shiny little kelly green crystals on a light brown matrix

Photo by Parent Géry CC BY-SA 3.0 https://commons.wikimedia.org/wiki/File:Grenat_var._uvarovite_%28Oural_-_F%C3%A9d%C3%A9ration_de_Russie%29.JPG

Uvarovite is a garnet group mineral, meaning that it’s structurally and compositionally similar to garnets, but unlike garnets, it is green. Uvarovite is named after Count Sergei Semenovitch Uvarov, a Russian statesman who was also quite the rockhound. It’s usually found in Russia, Spain, and Canada. The photo above is an extreme close-up, and may be misleading. Uvarovite crystals are usually about 2 mm long, so in “real life” it looks more like a plate of drusy quartz. Here’s how it looks from a bit farther away:

A plate of tiny green sparkly crystals of uvarovite.

Photo by Rob Lavinsky, retrieved from Mindat http://www.mindat.org/photo-118217.html

This specimen is from the Saranovskii Mine in Russia, and I think it’s quite pretty, don’t you?

Chondrodite on Magnetite

Photo by Rob Lavinsky, retrieved from Mindat at http://www.mindat.org/photo-37952.html

A shiny black chunk of pyramidal magnetite with glittering red crystals of chondrodite on top. It was found in the Tilly Foster Iron Mine in New York. Since it measures only 2.8 x 2.6 x 2.1 cm, if you’re on a desktop or tablet, you’re viewing it larger than actual size.

Magnetite and Pyrite Crystals

Black crystals of magnetite amid gold crystals of pyrite

Photo by Archeodontosaurus (CC BY-SA 3.0), retrieved from https://commons.wikimedia.org/wiki/File:Magnetite.jpg

Some cool looking black rhombododecahedral crystals of magnetite amid dull golden octahedral crystals of pyrite.

Granite

Did you know granite is not a mineral? Granite can’t be called a mineral because it is a mixture of many other minerals. Specifically, granite is a felsic (contains a lot of feldspar and quartz) intrusive (used to be liquid underground and was pushed up) igneous rock (made from magma or lava that has cooled and solidified) with at least 20% quartz and up to 65% alkali feldspar by volume. Sometimes it contains plagioclase feldspar, muscovite, biotite, and hornblende-type amphiboles as well. Different ratios of all these minerals in the mixture are what create all of the different colors and varieties of granite. Phew! That was a lot of definitions. If you need me, I’m going to drive by the granite store in Grandview. They leave their big slabs outside so you can look at them at any time of day. I guess granite slabs are too heavy to steal.

Photo by Jstuby from: https://en.wikipedia.org/wiki/File:Various_granites.jpg

Mozarkite

The Mozarkite Society of Lincoln, MO is having their annual rock show right now, from September 19-21. There is FREE admission! It is at the Lincoln City Park, Shelter House, behind Casey’s. Hours: Fri 9-5, Sat 9-4, Sun 9-4. Go to www.mozarkite.com for more information.

Mozarkite is a variety of quartz that comes in many colors including red, pink, purple, blue, and white, usually in pretty swirls. The name comes from Missouri and Ozarks, which is where mozarkite is often found. It is considered a semiprecious stone because it has a hardness of 7.5-7.75 on the Mohs scale, making it hard enough to be polished and made into jewelry. Mozarkite has been Missouri’s state rock ever since 1967.

Purple and blue mozarkite in an irregularly shaped rock and two polished green and purple mozarkite cabochons

Photos from the Mozarkite Society of Lincoln. http://www.mozarkite.com/samples.htm

Spying on IGAMS

We had loads of fun spying on the IGAMS (Independence Gem And Mineral Society) meeting to see what other rock clubs are up to. After all, there’s no rule against being in more than one club. We enjoyed seeing people’s rocks (Bruce had some nice loot from the Denver gem show), seeing our fellow rockhounds who we usually only see on special occasions, and listening to Mark Sherwood’s presentation on 3D printing. They also had great snacks. Meeting in a library is seriously limiting our snacking potential.

A man giving a presentation while standing next to a projector and a 3D printer.

Photo by Stephanie Reed

Mark Sherwood, the president of IGAMS, gave a presentation on 3D printing. He was printing out crystal models, just like the old wooden crystal models you sometimes see in museums.

About 15 people sitting or standing, looking at rocks and talking to one another.

Photo by Stephanie Reed

Rockhounds looking at each other’s rocks.

Yellow rutile stars in quartz

Clear colorless quartz with yellow rutilations that look like stars

Photo from: http://gem-sphalerite.com/inclusions-in-quartz-all-varieties/117-rutile-stars-inclusions-quartz-6864

This clear colorless quartz with yellow rutilations is too pretty not to share.

Big Red Petrified Wood

Photo by Stephanie Reed

A nice big chunk of petrified wood from the personal collection of David Reed, one of our members. It weighs over 100 pounds.

The Many Colors of Fluorite

Fluorite comes in just about every color of the rainbow, and is found all over the world in most areas of North America, Europe, and China. These are some of my favorite photos of fluorite.