Originating from Madagascar, grandidierite was discovered by French explorer Alfred Grandidier in 1902. Grandidierite is highly valued for its striking blue-green color, often compared to the vibrant hues of renowned paraíba tourmaline. Its combination of scarcity and remarkable beauty makes it a prized addition to fine jewelry, fetching high market value. The largest cut specimen currently known to the GIA weighs in at 763.5 carats.
Hardness:
7.5
Density:
2.98 - 2.99 g/cm³
On This Page
Properties
Characteristics
Common Questions
General Info About Grandidierite
Instantly Identify Rocks with a Snap
Snap a photo for instant rock/gemstone/mineral ID and properties analysis, gaining quick insights on characteristics, market value, collecting tips, care, real vs fake, and health risks, etc.
Download the App for Free
Physical Properties of Grandidierite
Luster
Vitreous, Pearly
Diaphaneity
Transparent to translucent
Colors
Bluish green, greenish blue
Magnetism
Non-magnetic
Tenacity
Brittle
Cleavage
Perfect
Fracture
Uneven
Streak
White
Crystal System
Orthorhombic
Hardness
7.5 , Extremely hard
Density
2.98 - 2.99 g/cm³, Normal Weight
AI rock expert in your pocket
Chemical Properties of Grandidierite
Chemical Classification
Silicates
Formula
(Mg,Fe²⁺)(Al,Fe³⁺)₃(SiO₄)(BO₃)O₂
Elements listed
Al,B,Fe,Mg,O,Si
Common Impurities
Ti,Mn,Na,K
Optical Properties of Grandidierite
Refractive Index
1.578-1.639
Birefringence
0.037-0.039
Pleochroism
Distinct: greenish blue, colorless, blue-green
Optical Character
Biaxial negative
Characteristics of Grandidierite
Your Comprehensive Rock Characteristics Guide
In-depth exploration of rock types, features, and formation aspects
Download the App for Free
Common Questions People Also Ask
Get Quick Rock Answers with a Snap
Snap a photo for instant rock ID and answers on characteristics, market value, collecting tips, care, real vs fake, and health risks, etc.
