Onyx

Onyx is a very popular gemstone composed of silicon dioxide. ^[1]

Onyx: Quick Facts and Characteristics

Some quick facts for Onyx:

• Transparency: Onyx can be opaque or translucent.
• Crystallography: In terms of crystallography, onyx can be hexagonal or trigonal.
• Luster: In terms of luster, onyx can be vitreous (glassy) or waxy.
• Streak: Onyx streaks white.
• Hardness: Onyx's hardness is 7 on the Moh's scale.
• Specific Gravity: Onyx's specific gravity is 2.651.

Onyx: Background and Summary

Onyx is a mineral that belongs to the chalcedony family, which is a type of quartz that is formed by the deposition of silica in the cavities of rocks. It is a cryptocrystalline mineral, which means that its crystals are too small to be seen with the naked eye. Onyx is typically black, but it can also be found in other colors such as white, gray, brown, and green. It has a waxy luster and a smooth, polished surface.

One of the easiest ways to identify onyx is by its color. Black onyx is the most common variety and is usually the easiest to find. However, it is important to note that not all black stones are onyx. Another way to identify onyx is by its hardness. Onyx has a hardness of 6.5 to 7 on the Mohs scale, which means that it is relatively hard and scratch-resistant.

Onyx has been used for a variety of purposes throughout history. It was often used in ancient times for carving cameos and intaglios, as well as for making jewelry and decorative objects. Today, onyx is still used for these purposes, as well as for making tiles and other architectural elements. It is also used in the manufacturing of high-end pens, watches, and other luxury items.