AMETHYST
Amethyst
Quartz
Purple quartz, sharing its mineral identity with citrine. Color zoning and growth patterns may be present.
GEM PROFILE
Basic properties
- Mineral or material
- Quartz
- Main chemical composition
- SiO₂
- Crystal & structure
- Trigonal
Hexagonal-looking prisms are characteristic. Crystals can grow inward from the walls of a geode.
- Typical colors
- Pale purple, deep purple and reddish purple
- Mohs hardness
- 7
A measure of scratch resistance, distinct from resistance to impact or breakage.
About hardness and durability - Representative sources
Examples of known sources. Determining the origin of an individual stone requires examination and comparison with reference material.
- Common cutting styles
- Rounds, ovals, step cuts, carvings and many other styles.
Explore cutting styles
LOOK A LITTLE CLOSER
What to observe
Bands of stronger and weaker color may be visible. Although its natural outline can look hexagonal, quartz is classified as trigonal in the seven-system convention.
TREATMENT & CARE
Treatments & care
Treatments & identification
Heating can alter its color. Synthetic amethyst is also available.
Everyday care
Use lukewarm water and mild detergent. Avoid high heat, sudden temperature changes and prolonged strong light.
Cleaning depends on treatment, inclusions and mounting. If a stone's condition is unknown, ask your jeweler or a gem specialist before cleaning.
READING & REFERENCES
References
Public sources for learning about this gemstone's general properties.
- GIA · Gemological reference
- GIA · Care & Cleaning
- Handbook of Mineralogy · Mineral data (PDF)
- GIA · Gem sources and fundamentals
This dictionary provides general educational information. Values are representative and do not identify or grade an individual stone. Locality examples include historical deposits.
Sources checked: October 19, 2026