About this stone
Color
ClearPinkPurpleYellowBrownGreenMulti
Origin
BrazilMadagascarUSA (Arkansas)IndiaChinaUruguayZambia
Mohs hardness
7
Treatment categories
NaturalHeatedIrradiated
Industry-standard treatment
Varies by variety — heat for citrine and prasiolite; irradiation common for smoky and lemon
Mineral chemistry
Silicon dioxide
Crystal system
Trigonal
Stone family
Quartz
Common cuts
Faceted RondelleRoundSmoothMicrofaceted RoundChip
Common sizes
2mm3mm4mm6mm8mm10mm
Care notes
Durable (Mohs 7). Ultrasonic and steam generally safe for natural material; confirm treatment on product page for irradiated or heated strands.
Related stones
Amethyst, Citrine, Rose Quartz, Smoky Quartz, Rutilated Quartz
Frequently asked questions
-
Is amethyst the same thing as quartz?
Yes. Amethyst is the purple variety of quartz — same chemistry (silicon dioxide), same Mohs 7 hardness, same crystal structure. The trace iron in the rough plus natural underground radiation produces the purple color. Citrine, rose, smoky, clear/rock crystal, ametrine, rutilated, and dozens of other named "stones" are all members of the quartz family. -
What's the difference between crystal quartz, clear quartz, and rock crystal?
They're three names for the same thing — colorless transparent quartz. The conventional bead-trade name is "Crystal Quartz" or "Rock Crystal." -
Is smoky quartz natural?
The brown-to-black color of smoky quartz is produced by gamma radiation acting on aluminum-bearing clear quartz. That radiation occurs naturally underground — but slowly. Most commercial smoky quartz on the bead market is clear quartz that was irradiated artificially in a lab to speed up the same process. The result is chemically identical to natural smoky quartz; irradiation, when known and disclosed by the supplier, should appear on the product page — ask before buying if treatment isn't specified. -
Is most "citrine" actually heat-treated amethyst?
Yes — by some industry estimates, around 90% of commercial citrine is heat-treated amethyst. Natural citrine is pale honey or champagne-colored; the bright orange "Madeira" tones most designers picture when they hear "citrine" are almost always the heat-treated product. Treatment status (natural vs. heat-treated amethyst) should appear on the product page — ask if a strand doesn't specify. -
Is "green amethyst" a real stone?
The green stone marketed as "green amethyst" is prasiolite — heat-treated amethyst that turned green rather than yellow under controlled heat. The FTC does not consider "green amethyst" an acceptable trade name. Use "prasiolite" if accuracy matters.