Gemstone profile and identification guide
Astrophyllite
Astrophyllite is a rare complex silicate mineral seen as bronze radiating blades in matrix material.
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Overview
Astrophyllite is a rare complex silicate mineral seen as bronze radiating blades in matrix material.
Did you know? The name means star-leaf, referring to radiating crystal aggregates.
Use this profile as a collector reference and educational guide for quick on-page comparison, then validate with the interactive identification system.
Identification
Name: Astrophyllite
Scientific classification: Silicate (Complex Titanium-Iron-Manganese Potassium Silicate)
Hardness: 3 Mohs
Transparency: opaque
Lustre: metallic to pearly
Crystal system: Triclinic
Primary colour: Bronze Brown
Secondary colour: Golden Brown
Colour family: Browns
Radiating bronze blades and matrix association are the key visual diagnostics.
Verification Status
Status: verified-core-fields
Reference priority: GIA, Gem-A, Mindat, International Gem Society
Core identity, locality, and physical-property fields reviewed against standard gemological references.
Values are reported as practical gemological ranges where appropriate.
Physical Properties
Hardness category: soft
Hardness value: 3 Mohs
Chemical composition: Complex hydrated potassium iron titanium silicate (species-variable)
Crystal system: Triclinic
Common locations: Russia (Kola Peninsula), Norway, Greenland, United States
Learn more: Gem-A gemstone education resources.
Colour Variations
Bronze to golden-brown radiating blades in dark host matrix.
Optical effects: Aster-like Radiating Pattern
Detailed Gemology
Mineral species: Astrophyllite
Mineral group: Complex silicate group
Chemical formula: Complex hydrated potassium iron titanium silicate (species-variable)
Mohs hardness: 3
Crystal system: Triclinic
Lustre: metallic to pearly
Transparency: opaque
Streak: Brownish yellow
Cleavage: Perfect in one direction
Fracture: Splintery to uneven
Specific gravity: 3.2-3.4
Refractive index: Typically high and variable in opaque material
Optical phenomena: Radiating star-like patterning
Colour range: Bronze brown to golden brown in dark matrix
Common inclusions: Matrix intergrowths, cleavage planes, accessory alkaline minerals
Geological environment: Alkalic pegmatites and syenitic intrusions
Principal mining regions: Russia (Kola Peninsula), Norway, Greenland, United States
Important commercial sources: Collector material is strongly associated with alkalic complexes in Russia and Norway
Historical significance: Primarily a collector mineral with niche lapidary use.
Common treatments: Generally untreated.
Synthetic or imitation forms: No common synthetic equivalent; resin composites may imitate appearance.
Common look-alikes: Bronzite aggregates, schiller feldspars
Jewellery uses: Used in cabochons and polished specimens emphasizing radiating patterns.
Care recommendations: Soft and cleavage-prone; suitable mainly for collector pieces and protected settings.
Cross-check profile data with GIA Gem Encyclopedia and Mindat entry for Astrophyllite.
Formation
Forms in alkalic igneous pegmatites and syenitic complexes.
Origin
Collector material is strongly associated with alkalic complexes in Russia and Norway
Uses
Best for: Used in cabochons and polished specimens emphasizing radiating patterns.
Ideal uses: Collector display and low-impact ornamental jewellery.
Care
Soft and cleavage-prone; suitable mainly for collector pieces and protected settings.
Need another candidate? Use advanced gemstone search or return to the identification guide.
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Commonly confused gemstones
Astrophyllite FAQ
How can I identify Astrophyllite?
Compare hardness (3 Mohs), crystal system (Triclinic), colour profile, and lustre (metallic to pearly) with your sample. Then cross-check related gemstones listed above.
What colour range does Astrophyllite appear in?
Bronze to golden-brown radiating blades in dark host matrix.
Where is Astrophyllite commonly used?
Collector display and low-impact ornamental jewellery.. For maintenance, follow the care guidance in this profile.
Scientific References
GIA: general gemstone identity (reviewed) - Batch 03 factual verification pass.
Gem-A: gemological terminology and testing references (reviewed) - Batch 03 factual verification pass.
Mindat: mineral species and principal localities (reviewed) - Batch 03 factual verification pass.
International Gem Society: gem trade context and treatment overview (reviewed) - Batch 03 factual verification pass.