What it is confused with
Glass, including cut lead crystal. Glass may show bubbles and warms quickly in the hand; quartz stays cool.
Colorless, transparent
Clear Quartz crystals
Clear Quartz is silicon dioxide (SiO₂), colorless, transparent, rated 7 on the Mohs scale. Traditionally, it is used as an amplifier and a blank slate for intention — attributed, not demonstrated.
- Mohs hardness
- 7 scratches window glass
- Crystal system
- Trigonal SiO₂
- Pliny, AD 77
- Book 37.9 as “crystallus”
- Main sources today
- Brazil also USA (Arkansas), Madagascar
Pliny, Natural History, tr. Bostock and Riley.
Is Clear Quartz a birthstone?
Yes. Clear Quartz is the alternative birthstone for April.
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Properties
Composition
Silicon dioxide (SiO₂)
Hardness (Mohs)
7
Crystal system
Trigonal
Color
Colorless, transparent
Mined in
Brazil, USA (Arkansas), Madagascar, Switzerland
Worth knowing
Quartz is genuinely piezoelectric: squeeze it and it produces voltage. That property runs watches and radios — one of the few crystal claims with physics behind it.
History
The Greek krystallos meant ice — they believed quartz was water frozen beyond thawing.
Buying
Buying Clear Quartz: fakes, value and treatments
What decides the price
Clarity and size, or interesting inclusions such as golden needles in rutilated quartz.
Where it is used
Quartz oscillators keep time in watches and computers, vibrating at a precise frequency when a voltage is applied.
A less familiar fact
Most quartz used in electronics is grown synthetically, because natural crystals are rarely pure enough.
Practical
Caring for Clear Quartz
How to clean it
Warm soapy water. Hard and safe in ultrasonic.
How to tell it is real
Glass is the common fake. Quartz stays cool to the touch; glass warms in the hand. Under magnification glass shows bubbles, quartz shows angular inclusions.
How hard is Clear Quartz?
Clear quartz is the yardstick itself — the Mohs scale defines 7 by quartz. With no color to fade, it is also one of the stones here that can go in an ultrasonic cleaner.
Clear Quartz, at 7, is harder than 28 of the other 42 stones here and softer than 9, with 5 level with it.
Primary source
What Pliny the Elder wrote about Clear Quartz
“crystal, a substance which assumes a concrete form from excessive congelation. At all events, crystal is only to be found in places where the winter snow freezes with the greatest intensity; and it is from the certainty that it is a kind of ice, that it has received the name which it bears in Greek.”
Pliny the Elder, The Natural History, translated by John Bostock and H. T. Riley (London: H. G. Bohn, 1855–57), book 37, chapter 9 — read the original text.
Greek krystallos meant ice. Rock crystal is quartz, silicon dioxide, which grows from hot solutions inside rock and has nothing to do with frozen water. Who Pliny was and why we quote him →
Traditional associations
Clear Quartz is traditionally used as an amplifier and a blank slate for intention. Chakra in crystal practice: All, particularly Crown. Element: All.
Questions about Clear Quartz
What is Clear Quartz made of?
Silicon dioxide (SiO₂), crystallizing in the trigonal system.
Which month is Clear Quartz the birthstone for?
Only as an alternative stone, for April.
Where does Clear Quartz come from?
Brazil, USA (Arkansas), Madagascar, Switzerland.
Can Clear Quartz be worn every day?
Yes, and it is easy to live with: at 7 on the Mohs scale, it has no color to fade and is even safe in an ultrasonic cleaner.
Sources
Statements of fact on this page were checked against these sources in October 2026. How we choose and check sources: editorial policy.
Cite this page
AstroHot. “Clear Quartz Crystals: Meaning, Hardness and Origins.” Accessed October 28, 2026. https://astrohot.com/crystals/gemstones/clear-quartz/
For Wikipedia
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