Gem Identification
Comprehensive identification tools including side-by-side gem comparison, Mohs hardness reference, and cleavage/fracture patterns.
Gem Identifier
Multi-property search to identify unknown gemstones
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Hardness Reference
Mohs scale lookup with wearability ratings
Mohs Scale
| 10 | Diamond |
| 9 | Corundum (Ruby/Sapphire) |
| 8 | Topaz / Spinel |
| 7.5 | Beryl (Emerald / Aquamarine) |
| 7 | Quartz |
| 6.5 | Tanzanite / Peridot |
| 6 | Feldspar (Moonstone) |
| 5 | Apatite |
| 4 | Fluorite |
| 3 | Calcite |
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• Hardness = resistance to scratching• Toughness = resistance to breaking (not the same thing)• Diamond is hard but has perfect cleavage; jade is softer but tougher
Fracture & Cleavage Guide
Cleavage directions and fracture pattern identification
Fracture Types
Conchoidal
Smooth, curved surfaces like broken glass
Quartz, obsidian, most amorphous materials
Uneven
Rough, irregular surfaces
Most crystalline gems, corundum, garnet
Splintery
Fractures into elongated splinters
Fibrous minerals, some tourmalines
Hackly
Jagged, sharp points
Native metals, some sulfides
Cleavage Reference
15 gems
| Gemstone | Cleavage | Directions | Fracture | Notes |
|---|---|---|---|---|
| Diamond | Perfect | 4 directions (octahedral) | Conchoidal | Cleaves easily - avoid sharp blows |
| Topaz | Perfect | 1 direction (basal) | Conchoidal to uneven | Very easy to cleave - handle carefully |
| Kunzite | Perfect | 2 directions (prismatic) | Uneven | Extremely fragile - not for rings |
| Feldspar (Moonstone) | Perfect | 2 directions (90°) | Uneven to conchoidal | Two perfect cleavages at right angles |
| Tanzanite | Perfect | 1 direction (basal) | Uneven to conchoidal | Very fragile - protective settings required |
| Emerald | Indistinct | 1 direction (basal) | Conchoidal to uneven | Usually heavily included - brittle |
| Aquamarine | Indistinct | 1 direction (basal) | Conchoidal to uneven | Better toughness than emerald |
| Quartz | None | None | Conchoidal | Excellent toughness - very durable |
| Garnet | None | None | Conchoidal to uneven | No cleavage - good durability |
| Spinel | None | None | Conchoidal | Excellent toughness - very durable |
| Ruby | None | None (parting sometimes) | Conchoidal to uneven | Excellent toughness - very durable |
| Sapphire | None | None (parting sometimes) | Conchoidal to uneven | Excellent toughness - very durable |
| Chrysoberyl | Distinct | 3 directions | Conchoidal to uneven | Good toughness despite cleavage |
| Tourmaline | Indistinct | None to indistinct | Uneven to conchoidal | Can be brittle - avoid sharp blows |
| Peridot | Distinct | 2 directions | Conchoidal | Moderate toughness |
• Perfect cleavage splits easily along smooth planes• Cleavage = along crystal planes; Fracture = random breaking• Avoid ultrasonic cleaning for gems with perfect cleavage• Use bezel or protective settings for fragile gems