Gemstone Identification Guide: Mineral Properties, Hardness & Value
Here is list of Gemstone properties, information about minerals and other classifications. This will help in gemstone identification
| Gemstone Properties | Mineral Information | Other Classifications & Special Categories |
|---|---|---|
| Anisotropism: Directional optical properties (e.g., Tanzanite) | Chemistry: Chemical composition (e.g., Corundum = Al₂O₃) | Country of Origin: Geographic sources (e.g., Colombian Emerald) |
| Birefringence: Double refraction (e.g., Calcite) | Crystallography: Crystal systems (e.g., Cubic, Hexagonal) | Diamagnetic Gems: Repel magnetic fields (e.g., Quartz) |
| Clarity: Inclusions/vacuoles (e.g., VVS diamonds) | Density (Specific Gravity): Mass/volume ratio (e.g., Zircon = 4.6–4.7) | Magnetic Gems: Attracted to magnets (e.g., Magnetite) |
| Cleavage: Tendency to split (e.g., Topaz) | Refractive Index: Light-bending ability (e.g., Diamond = 2.42) | Metallic Gems: Metal-like luster (e.g., Pyrite) |
| Colours: Hue variations (e.g., Sapphire’s blue) | Strunz Classification: Mineral taxonomy (e.g., Silicates) | Photochromic Gems: Color change under light (e.g., Hackmanite) |
| Crystal Habit/Shapes: Natural forms (e.g., Cubic Fluorite) | Mineral Groups: Families (e.g., Beryl, Feldspar) | Piezoelectric Gems: Generate charge under pressure (e.g., Quartz) |
| Dispersion: Fire/sparkle (e.g., Demantoid Garnet) | Polymorphous: Same chemistry, different structures (e.g., Andalusite/Kyanite) | Pyroelectric Gems: Charge with temperature change (e.g., Tourmaline) |
| Fracture: Breakage pattern (e.g., Conchoidal in Obsidian) | Dimorphous: Two structures from same compound (e.g., Rutile/Anatase) | Radioactive Gems: Emit radiation (e.g., Uraninite) |
| Hardness (Mohs Scale): Scratch resistance (e.g., Diamond = 10) | Trimorphous: Three structures (e.g., Al₂SiO₅ polymorphs) | Poisonous Gems: Toxic when handled (e.g., Cinnabar) |
| Luster: Surface reflection (e.g., Vitreous, Adamantine) | Pseudomorph: Replacement minerals (e.g., Petrified Wood) | Water-Soluble Gems: Dissolve in water (e.g., Halite) |
| Optical Illusion: Phenomena (e.g., Asterism in Star Sapphire) | Rare Earth Elements: Presence in minerals (e.g., Monazite) | Zodiac Gemstones: Astrological links (e.g., Garnet for Aquarius) |
| Pleochroism: Multi-color viewing angles (e.g., Iolite) | Twinning: Crystal intergrowths (e.g., Carlsbad Twin in Orthoclase) | USA Gemstones: Notable U.S. gems (e.g., Montana Sapphire) |
| Transparency: Light passage (Transparent to Opaque) | Mineral Classifications: Categories (e.g., Oxides, Carbonates) | US State Gemstones: Official state stones (e.g., Turquoise for Nevada) |
| Tenacity (Toughness): Resistance to breakage (e.g., Jade = Tough) | Shapes of Gemstones: Cut forms (e.g., Brilliant, Cabochon) | Enhancements: Treatments (e.g., Heat-treated Rubies) |
| Tenebrescent Gems: Reversible color change (e.g., Hackmanite) | Crystallography: Symmetry and axes (e.g., Tetragonal Zircon) | Triboluminescent Gems: Light under friction (e.g., Sphalerite) |
