Smoky Quartz in Calcite

528g raw smoky quartz in calcite. This beautiful stone is composed of small smoky quartz crystals embedded in calcite. The caramel brown color of the quartz displays varying shades, from lighter to darker. The stone measures 140 x 100 x 40 mm and originates from Argentina. The combination of colors and its unique formation make it a one-of-a-kind collector's item. Quartz is a mineral composed of silica (SiO2). Quartz crystals form over a very long period. The process occurs deep within the Earth and requires high temperatures, pressure, and, of course, time. It is one of the most abundant minerals in the Earth's crust. Its color is due to the presence of trace amounts of aluminum combined with the effects of radioactivity. Origin: Argentina