Blue Chalcedony
A variety of Chalcedony
What is Blue Chalcedony?
Blue Chalcedony is a highly prized gemstone. The blue variety of Chalcedony occurs only when it does not contain many color-changing impurities. This stone is perfect for carving, cutting, crafting, and tumbling, and its rarity may explain why so many Chalcedonies are artificially colored for the market. The most valuable natural specimens of blue Chalcedony bend the light in such a way that they appear to be lit from within.
Optical Properties
- Refractive Index
- 1.530-1.543
- Birefringence
- 0.003-0.009
- Pleochroism
- None
- Optical Character
- Biaxial positive
- Dispersion
- 0.013
Discover Values
This stone excels in beauty.
Blue Chalcedony Market Value Calculator
Estimate the market value of Blue Chalcedony using size, quality, and finish. This preview calculator is for quick context and is not a formal appraisal.
Blue Chalcedony Localities Map
See where Blue Chalcedony is found with a localities map, collecting zones, and geology context. Generate a sample map preview below.
Health & Safety Information
- ⚠️Harm Reason: Blue 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 Blue Chalcedony?
Quick Facts
Physical Properties
- Color
- Blue
- Hardness (Mohs)
- 6.5 - 7
- Density
- 2.55 - 2.7 g/cm³
- Streak
- White
- Luster
- Waxy
- Crystal System
- Trigonal
Chemical Properties
- Chemical Formula
- SiO2
- Elements
- O, Si
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