Smoky quartz is known for its large, well-formed, translucent to transparent crystals.
The colour is produced when impurities of aluminium in the surrounding rock react to radiation.
Colour can vary from a subtle brown to yellowish-brown to a shade so dark it almost looks black.
A considerable amount of smoky quartz sold commercially is clear quartz that's been heated.
Natural smoky quartz fades when exposed to high temperatures.
Smoky quartz is one of only a few brown-coloured crystals from which gemstones are cut.
It's common for smoky quartz crystals to be inclusion-free.
SHUNGITE
