Smoky quartz is believed in crystal healing to ground and protect, but there is no scientific evidence of benefits. It is valued as a decorative stone.
Beliefs
In crystal healing, smoky quartz is said to ground, protect and remove negativity.
Evidence
No scientific evidence shows healing effects.
What it is
A brown to gray variety of quartz. Its color comes from natural radiation exposure to aluminum in the crystal. Hardness 7.
Uses
Jewelry and decoration.
Placebo
Some people find rituals calming.
Note
Don’t use instead of medical care.
What smoky quartz is
Smoky quartz is a variety of quartz (silicon dioxide) colored brown to nearly black by natural radiation acting on aluminum impurities in the crystal. It has a Mohs hardness of 7 and is common in Brazil, Switzerland, Scotland and the US. The Scottish national gemstone is known as Cairngorm, a smoky quartz.
- Heating to 300 to 400 C can lighten the color, and some stones on the market are irradiated to darken them.
- It is used in jewelry and carvings, and is generally inexpensive compared with other gemstones.
- Crystal healing claims, such as grounding or removing negative energy, come from New Age tradition.
Evidence
No scientific evidence shows that smoky quartz has healing properties. Any perceived benefit is likely due to placebo effects, relaxation or meaning attached to holding the stone. A study in the journal Psychological Science (2010s) on healing crystals found that people reported effects regardless of whether the crystal was real. Do not replace medical care with stones.
What smoky quartz is
Smoky quartz is a gray to brown form of crystalline silica (SiO2) colored by natural radiation acting on aluminum impurities. It is the national gem of Scotland, where it is called cairngorm. Hardness is 7 on the Mohs scale.
Evidence
Metaphysical claims about protection or stress relief are not supported by scientific evidence. Any calming effects likely come from placebo and ritual. Enjoy it as a mineral.
Geology and sources
Smoky quartz forms when natural radiation from surrounding rocks acts on aluminum impurities in quartz crystals. Large crystals come from the Swiss Alps, Brazil, Scotland (Cairngorm mountains) and Madagascar. Heat treatment of amethyst or citrine can also change color. The hardness is 7 and the specific gravity 2.65.
Market and care
Smoky quartz is relatively inexpensive, at a few dollars to about 50 USD per carat for fine gems. It is safe to clean with warm soapy water and avoid sudden heat. Claims of healing powers are not supported by clinical trials. Watch for dyed or irradiated stones sold as natural.
Based on data from the Gemological Institute of America and the Smithsonian
