Polished Smoky Quartz Pebble from Brazil - 5.3 cm / 79g

SMOKY QUARTZ belongs to the silicate group. It mainly contains silicon. Its chemical formula is SiO2.

It comes in massive or prismatic crystals. Depending on the impurities they contain, these minerals display various colors such as pink, yellow, blue, purple, or black.

The colorless mineral QUARTZ is called rock crystal. SMOKY QUARTZ owes its color to impurities reacting with the radioactivity released by certain minerals such as Torbernite.

The mineral QUARTZ is a very common mineral found in almost all types of rock. Quartz has a hardness of 7/10 on the Mohs scale (10 for diamond) and a specific gravity of 2.7 (1 for water). The line on porcelain is white.

The name Quartz comes from German.