Rockhounding in Kentucky – What Rocks You Can Find and Where

Rockhounding Events in Kentucky

[tribe_events_list tags=”kentucky” limit=”5″]

Bituminous Coal

Hardness: 2 – 2.5

Streak: Black

Chemical Formula: C₁₃₇H₉₇O₉NS

Bituminous Coal is one of the four recognized varieties of coal. It is the most abundant and it frequently used for heat generation, but it not as efficient as Anthracite Coal which is the highest grade of coal.

Bituminous Coal is relatively soft and contains the tar-like substance asphalt or bitumen. It is generally black in color or dark brown, featuring well-defined bands of bright and dull material.

Coal in general is an organic sedimentary rock formed from the fossilized remains of plants. It generally occurs in layered, sedimentary deposits.

Fluorite

Hardness: 4

Streak: White

Chemical Formula: CaF₂

Composed of Calcium and Flourine, Fluorite is a very popular mineral. It commonly occurs as well-formed, colorful crystals. Pure fluorite is colorless, but various impurities cause the wide spectrum of colors that fluorite crystals are known for.

Fluorite is also well-known for its ability for some specimens to fluoresce under ultraviolet light. Even their fluorescent colors can vary from blue to a white or cream color.

Fluorite is created by hydrothermal processes as an accessory mineral in silica-rich rocks. It is often found in veins containing metallic ores such as sulfides of tin, lead, zinc, and copper.

Fluorite has a wide variety of uses today and is referred to as Fluorspar when sold as a bulk material. Fluorite is used in manufacturing hydrofluoric acid, ceramics, and as flux for removing impurities in metal production.

Fluorite can also be a beautiful gemstone when faceted, but because of it’s relatively low hardness of 4 it is not commonly used.