Green Chalcedony
Chrysoprase
A variety of Chalcedony
What is Green Chalcedony?
Green Chalcedony is an attractive and highly popular variety of Chalcedony that gets its apple-green color from its nickel content. It consists of a number of randomly oriented small crystals; thanks to these microcrystals, green Chalcedony appears to transmit light constantly when rotating through 360 degrees. It is regularly cut into gems, beads, and cabochons. Green Chalcedony is a birthstone of May.
Optical Properties
- Refractive Index
- 1.530-1.543
- Birefringence
- 0.004
- Pleochroism
- None
- Optical Character
- Biaxial positive
- Dispersion
- 0.013
Discover Values
Green Chalcedony Market Value Calculator
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Green Chalcedony Localities Map
See where Green Chalcedony is found with a localities map, collecting zones, and geology context. Generate a sample map preview below.
Key Characteristics
Characteristics of Green Chalcedony
As with all forms of chalcedony, chrysoprase has a hardness of 6–7 on the Mohs hardness scale and a conchoidal fracture like flint.
Formation of Green Chalcedony
Chrysoprase results from the deep weathering or lateritization of nickeliferous serpentinites or other ultramafic ophiolite rocks. In the Australian deposits, chrysoprase occurs as veins and nodules with brown goethite and other iron oxides in the magnesite-rich saprolite below an iron and silica cap.
Health & Safety Information
- ⚠️Harm Reason: Green Chalcedony in powdered form can be toxic due to its Crystalline Silica content.
- ⚠️Physical Toxicity: Quartz, silica, crystalline silica and flint are non-toxic materials, but very fine dust containing quartz, known as respirable crystalline silicon (RCS), can cause serious and fatal lung disease. Lapidaries should exercise caution when cutting silica.
- ⚠️How to prevent the risks of Green Chalcedony?
Quick Facts
Physical Properties
- Color
- Apple-green, green
- Hardness (Mohs)
- 6.5 - 7
- Density
- 2.65 - 2.66 g/cm³
- Streak
- Brown, white
- Luster
- Waxy
- Crystal System
- Trigonal
Chemical Properties
- Chemical Formula
- SiO2
- Elements
- O, Si
Also Known As
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