Green Onyx
A variety of Calcite
What is Green Onyx?
Green Onyx is a false variety of onyx, which usually only occurs in translucent and opaque black and white colors. Onyx is and always has been a popular gemstone, though it has greatly diminished in value over the years. Green Onyx is most commonly a Chalcedony or a variety of silica that has been dyed.
Optical Properties
- Refractive Index
- 1.486-1.658
- Birefringence
- 0.172
- Pleochroism
- None
- Optical Character
- Uniaxial negative
- Dispersion
- 0.008-0.017
Discover Values
Market Value Factors
Pricing varies for every rock and mineral, so use these universal factors to gauge Green Onyx before comparing listings or appraisals.
Size & Weight
Larger, intact specimens usually command higher prices.
Rarity & Demand
Scarce material or popular varieties sell at a premium.
Condition & Finish
Chips, repairs, and heavy wear lower value; clean prep helps.
Treatment & Provenance
Untreated specimens with documented locality are prized.
Where to Find Green Onyx
Green Onyx is a variety of Calcite. RockHoundR, the free-to-download rockhounding map from the Ruby Glint team, shows where collectors find calcite in the US, with land-access notes for BLM land and national forests. Collecting is banned in national parks.
See where to find calciteAlways check the local rules and get the landowner's permission before you collect.
Quick Facts
Physical Properties
- Color
- Light to dark green with white, red or brown bandings
- Hardness (Mohs)
- 3
- Rock tumbling
- Tumbles well
- Density
- 2.65 - 2.75 g/cm³
- Streak
- White
- Luster
- Vitreous, Waxy
- Crystal System
- Hexagonal
Chemical Properties
- Chemical Formula
- SiO2
- Elements
- C, Ca, O
Identify Green Onyx Instantly
- Snap a photo, get instant results
- 6,700+ rocks, minerals & crystals
- Discover collecting spots near you
Green Onyx FAQs
How do I identify Green Onyx?
Green Onyx can be identified by its hardness of 3 on the Mohs scale, Light to dark green with white color, Vitreous, Waxy luster, Hexagonal crystal system. Look for these key characteristics when examining specimens.
What color is Green Onyx?
Green Onyx typically appears in Light to dark green with white, red or brown bandings. Color can vary depending on impurities and formation conditions.
How hard is Green Onyx?
Green Onyx has a hardness of 3 on the Mohs scale. This makes it a soft mineral that can be scratched easily.