Smoky Quartz is the brown variety of quartz, ranging from light brownish-gray to black. It can vary from almost completely transparent to nearly opaque.
It has a hardness of 7 on the Mohs scale and is available in a wide range of faceted shapes and sizes.
Quartz is the chemical compound, silicon dioxide or silica. It is the second most abundant mineral in Earth’s continental crust, a component in granite, sandstone, schist and shale to name a few.
Pure quartz, traditionally called rock crystal is colourless and transparent or translucent. The coloured varieties of quartz occur due to built-in trace elements or inclusions of other minerals.
Many forms of quartz are used as gemstones and they are all affordable. They are cut into various gemstone cuts and cabochons, and used in all forms of jewelry. The wide range of colour, lack of cleavage and good durability and wide availability combine to make quartz is a very popular semi-precious gemstone option.
Gemstone varieties are divided into two main groups:
- Varieties that develop visible crystals or are made of large inter-grown crystals. They tend to be transparent to translucent and include Amethyst, Citrine, Smoky quartz, Rose quartz, Green quartz, Rutilated quartz and Adventurine.
- Any form of Quartz composed of tiny crystals that cannot be seen with an unaided eye. Known as Chalecedony they tend to be translucent to opaque and include multi-coloured Agate, Carnelian, Tiger’s Eye, Chrysoprase, Onyx and Jasper.