Clear Quartz
Also Rock crystal
The pure form of the second most common mineral on Earth.
- Family
- Quartz
- Formula
- SiO₂
- Mohs
- 7
- System
- Trigonal
Drag to turn
Science
Rock crystal is quartz with no colouring impurities. It grows as six-sided prisms capped by six-sided pyramids, often in the hollow veins and clefts of granite. Its piezoelectric response is the basis of every quartz watch and the timing crystal in most electronics.
- Mineral
- Quartz
- Formula
- SiO₂
- Crystal system
- Trigonal
- Mohs hardness
- 7
- Specific gravity
- 2.65
- Refractive index
- 1.544 to 1.553
- Lustre
- Vitreous
- Colours
- Colourless, White
Composition
SiO₂. Made of Silicon, Oxygen.
Origin
- Brazil
- United StatesArkansas, Herkimer NY
- Madagascar
- SwitzerlandAlps
- China
- Pakistan
Filled dots are primary sources
Rarity
Quartz is roughly twelve percent of the continental crust. Flawless large crystals are still prized.
- 1 Abundant
- 2 Common
- 3 Uncommon
- 4 Rare
- 5 Exceptional
Hardness
Clear Quartz sits at 7 on the Mohs scale. It will scratch glass and holds a polish in daily wear.
Energy
Associations from crystal-healing tradition, recorded here as folklore. They are not medical claims.
Chakras
- Crown
Element
- Storm
Zodiac
- Aries
- Leo
- Capricorn
Planets
- Sun
- Moon
Properties
- Amplification
- Clarity
- Focus
- Programming
- Purification
Lore
The Greek krystallos meant ice; classical writers believed rock crystal was water frozen so hard it could never melt. Roman women carried quartz spheres to cool their hands in summer.
Scrying spheres, Japanese tama, Aboriginal healing stones and medieval reliquaries all used clear quartz. In modern practice it is the universal amplifier, paired with any other stone.
- PiezoelectricSqueezing quartz produces a voltage, discovered by the Curie brothers in 1880.
- HerkimerDoubly terminated crystals from New York, marketed as 'Herkimer diamonds'.