Ankerite

The crystalline properties of annabergite can range on the color spectrum from pearlescent pink to grassy-green, with brilliant green being most common and desirable. Cobalt concentration causes the variable colors. It is exceptionally rich in nickel and rare to find, with only one large deposit in Greece.

Millerite has a rich yellow color. It is typically not used for jewelry, as its very low hardness makes it unsuitable for wear. Therefore, as gem material for decorative objects, it also rarely appears on offer by gem makers. However, millerite crystals can also have an unusual, hair-like appearance and attract the interest of mineral collectors.

Cerussite, also known as "white lead," has been industrially mined for several centuries (lead has historically been used in a wide variety of industrial processes and alloys). It can crystalize into some truly striking forms. "Twined" specimens have crystals that appear to be interwoven, with empty space in between. Gemstone-quality crystals are rare, but breathtaking, such as the spectacular 898-carat "Light of the Desert" which was found in Namibia.

Benitoite is a scarce and precious stone, so precious in fact it has been bestowed the honor of being the State Gemstone of California. Cut and polished specimens of benitoite are costly, commanding up to $5,000 per carat when perfect clarity and color are present. It is not a gem you'll see in most collections!

Scorodite has fascinating color-changing properties in different lights, but the most memorable part of this mineral is that, when heated, it emits a powerful garlic odor. This odor is caused by its high arsenic concentration, which makes it less than desirable. Scorodite can cause severe discomfort when handled, or if dust is inhaled.

Anglesite is a lead-containing mineral that forms crystals of varying colors. Occasionally mined for its lead content (lead has tons of commercial and industrial uses), high-quality specimens are also sought after by collectors. Crystals occasionally exhibit exquisite colorations, with blue, green, orange, violet, and yellow-hued varieties being particularly prized. Though found in multiple locations across the world, many collector-quality anglesites come from Morocco.

When studied under different light sources, ilvaite will almost magically change colors depending on how you look at it. It isn't the dull black gem that you might think! It was first found on Elba Island off the coast of Italy back in 1811.

Greenstone is a field term used to describe any dense, dark-green altered or metamorphosed basic igneous rock. The distinctive green color of greenstone is typically caused by the presence of epidote, actinolite, or chlorite.