Valentinite

Libethenite was discovered in the village of Ľubietová, Slovakia, and it was named after the German word for the village - Libethen. It is a relatively rare copper mineral that is commonly found in the form of beautiful, deep-green or olive green translucent crystals.

Cyanotrichite is a beautiful but extremely fragile mineral. It comes in several crystal forms; the round, plush-like, "hairy" crystal formation is certainly the most attractive. The specimens are quite small (micromounts), so they are regularly kept in small transparent boxes and enjoyed under magnified view. Cyanotrichite is a very rare mineral, closely associated with copper.

Nepheline is a rock-forming mineral which sometimes occurs in recent lava flows as glassy crystals. This mineral is usually white in color, often with a gray or yellowish tint. It is often very large and found in unattractive specimens. Its main uses are for mineral collections and raw material for special kinds of ceramics and glass.

Lavendulan is an uncommon mineral known for its electric blue translucent color. It is a secondary mineral sometimes found in copper-arsenic deposits. Lavendulan may be mistaken for mahnertite or slavkovite superficially. It also belongs to the Lavendulan group, which contains sampleite and zdenekite as well.

Crocoite is a highly-sought but rare mineral, prized for its beautiful deep orange-red color. It once was a main ore of Chromium, but now it's rarely used for that purpose. This eye-catching mineral is, unfortunately, too fragile to be used for jewelry, but it's still prized by mineral collectors. It is toxic.

Anthracite, the highest grade of coal, is a metamorphic rock renowned for its lustrous appearance, hardness, and ability to burn with a clean, smokeless flame. With its elevated carbon content and low impurity levels, anthracite is prized for its high energy value, making it particularly valuable for industrial and residential use. The anthracite fields in Pennsylvania, USA have been a significant source of this coal for many years. Other countries that have notable anthracite reserves include China, Russia, Ukraine, and South Africa.

Acanthite is supersaturated in silver and is the most predominant mineral mined to refine this element. A massive cache of acanthite was found in 1859 in Nevada, USA, causing a major silver rush to that state. A new mint was built close by just to process the massive amounts of silver being unearthed.

Kämmererite is a beautiful but extremely rare rock material — only ever discovered in a few places in the world. This red to violet stone is difficult to facet, so cut gems are very rare and therefore valuable. Due to their rarity and softness, these stones are mostly reserved for hobbyists and rarely used with jewelry.