Minerals

Spessartine

You may remember our earlier post about uvarovite, the green garnet.  Spessartine is another garnet group mineral.  Notice how similar the crystals look, except for spessartine being reddish orange (and a bit of yellow in there, too) and uvarovite being green.  It is named after where it was first found: the German city Spessart, in the state of Bavaria.  The specimen pictured was found in the Broken Hill district in New South Wales, Australia.  It can also be found in Madagascar, China, Myanmar, India, Afghanistan, Israel, and parts of the United States such as Maine and Colorado.  Look for it in granite pegmatite and also sometimes in metamorphic phyllites.

If you liked these posts, you may wish to research the other garnet group minerals: almandine (purplish-red to orangish-red), andradite (can be black, green, or yellow-green), grossularite (brown to yellow), pyrope (very dark red to black), and tsavorite (light to dark green).

Uvarovite

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
A shiny black chunk of pyramidal magnetite with glittering red crystals of chondrodite on top

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.

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

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.

Red fluorite crystals

Photo by Rob Lavinsky, iRocks.com – CC-BY-SA-3.0 https://www.cs.cmu.edu/~fluorite/fluorite_image.html

Fluorite is pretty on its own, but it’s simply amazing how the most common minerals look so awesome when made into these polished spheres.