Smoky quartz is one of only a few black or brown coloured minerals from which gemstones are cut. Others varieties include smoky topaz, black beryl which is relatively rare and brown corundum. Smoky quartz is often confused for smoky topaz but quartz and topaz are two completely different minerals.
The colour of this translucent mineral can vary from light brown to yellowish brown to a shade of brown that's so dark it almost appears to be black. Smoky quartz often forms large crystals with few inclusions and because of its abundance it's not particularly expensive. Cairngorm is a variety of smoky quartz that's mined on Cairn Gorm, a mountain in the Eastern Highlands of Scotland. Stones from this location have a smoky yellowish brown colour but may also be greyish brown.
In crystal healing smoky quartz is said to have the ability to transform negative energy and is particularly effective in dealing with anger and resentment. It's useful for alleviating panic attacks, anxiety and nightmares and can form a shield around the user to protect them from negative energy.
On Mohs scale of mineral hardness smoky quartz grades 7 which makes it ideal for use as a lapidary material. It can be found in several locations worldwide including Australia, Brazil, India, Kazakhstan, Madagascar, Russia, Zimbabwe, South Africa, Tanzania, Ukraine, Switzerland and USA.
Additional information on smoky quartz