Gemstone profile and identification guide
Apophyllite
Apophyllite is a hydrated silicate mineral group known primarily as collector crystal material and occasional faceted gem.
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Overview
Apophyllite is a hydrated silicate mineral group known primarily as collector crystal material and occasional faceted gem.
Did you know? Indian trap-rock geodes produce some of the world’s best-known apophyllite specimens.
Use this profile as a collector reference and educational guide for quick on-page comparison, then validate with the interactive identification system.
Identification
Name: Apophyllite
Scientific classification: Silicate (Phyllosilicate Group: Apophyllite Supergroup)
Hardness: 4.75 Mohs
Transparency: transparent
Lustre: vitreous to pearly
Crystal system: Tetragonal
Primary colour: Colorless
Secondary colour: Green
Colour family: Whites & Neutrals
Tetragonal crystal habit, perfect cleavage, and moderate hardness are key indicators.
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: medium
Hardness value: 4.75 Mohs
Chemical composition: Potassium calcium silicate fluoride hydroxide hydrate (variable species)
Crystal system: Tetragonal
Common locations: India (Maharashtra), Brazil, Iceland, Germany, Canada
Learn more: Gem-A gemstone education resources.
Colour Variations
Typically colorless to white, with pale green crystal specimens common in collector material.
Optical effects: None specified in the current dataset.
Detailed Gemology
Mineral species: Apophyllite supergroup species
Mineral group: Phyllosilicate group
Chemical formula: Potassium calcium silicate fluoride hydroxide hydrate (variable species)
Mohs hardness: 4.75
Crystal system: Tetragonal
Lustre: vitreous to pearly
Transparency: transparent
Streak: White
Cleavage: Perfect basal cleavage
Fracture: Uneven
Specific gravity: 2.30-2.40
Refractive index: 1.535-1.551
Optical phenomena: None typically diagnostic
Colour range: Colorless, white, pale green
Common inclusions: Fluid inclusions, growth zoning, matrix contacts
Geological environment: Basalt cavities and hydrothermal veins
Principal mining regions: India (Maharashtra), Brazil, Iceland, Germany, Canada
Important commercial sources: Most gem and collector apophyllite on the market comes from basalt cavities in India
Historical significance: Widely collected in modern mineral collecting due to crystal clarity.
Common treatments: Generally untreated.
Synthetic or imitation forms: Glass may imitate transparent crystal appearance.
Common look-alikes: Calcite, quartz, prehnite (in matrix)
Jewellery uses: Used mainly as collector specimens and rarely as faceted stones.
Care recommendations: Soft with perfect cleavage; handle gently and avoid ultrasonic/steam cleaning.
Cross-check profile data with GIA Gem Encyclopedia and Mindat entry for Apophyllite.
Formation
Forms in low-temperature hydrothermal cavities, commonly in basaltic volcanic rocks.
Origin
Most gem and collector apophyllite on the market comes from basalt cavities in India
Uses
Best for: Used mainly as collector specimens and rarely as faceted stones.
Ideal uses: Display specimens and low-impact collector jewellery.
Care
Soft with perfect cleavage; handle gently and avoid ultrasonic/steam cleaning.
Need another candidate? Use advanced gemstone search or return to the identification guide.
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Apophyllite FAQ
How can I identify Apophyllite?
Compare hardness (4.75 Mohs), crystal system (Tetragonal), colour profile, and lustre (vitreous to pearly) with your sample. Then cross-check related gemstones listed above.
What colour range does Apophyllite appear in?
Typically colorless to white, with pale green crystal specimens common in collector material.
Where is Apophyllite commonly used?
Display specimens and low-impact collector 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.