Gemstone Identifier —
What Gem Is This?
Upload a photo of any faceted gem, cabochon, rough stone, or bead. Our AI identifies the gemstone species, assesses quality, flags synthetics and simulants, and gives you an expert result in seconds — free, no sign-up required.
What You Get in Every Result
- Gemstone name and scientific mineral species
- Confidence percentage with full reasoning
- Natural vs synthetic vs simulant assessment
- Colour grade, luster type, and clarity notes
- Mohs hardness and crystal system
- Rarity rating and collector value indication
- Common locations where this gem is found globally
- Similar gemstones and how to tell them apart
- Care instructions and authentication tip
Gemstone Identifier
Upload photos of faceted stones, cabochons, beads, rough, or crystals — get an AI identification with likely species, treatments to consider, and collector notes.
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Description
Origin / formation
Hardness (Mohs)
Luster
Rarity
Relative value
Notable localities / regions
Typical colours
Key properties
Similar gemstones
Alternative identifications
Gemstones Our AI Identifies
Our gemstone identifier covers more than 100 mineral species across every category — from the rarest precious stones to the most common collector minerals. Whether your stone came from a jeweller, a market stall, a rock show, or a riverbed, our AI will tell you what it is.
The traditional Big Four — the rarest, most commercially valuable gems. Colour, clarity, cut, and carat weight are the primary value drivers.
Hundreds of species fall into this category — value varies enormously based on colour saturation, origin, and rarity within the species.
A note on the precious vs semi-precious distinction
The terms “precious” and “semi-precious” are trade conventions, not scientific categories. A fine alexandrite or Paraíba tourmaline can be worth many times more per carat than a mediocre ruby. Our AI identifies the mineral species and gives you quality indicators — the market value always depends on the specific stone’s grade, origin, and treatment history.
Common Gemstone Species — Quick Reference
Each gemstone belongs to a mineral species defined by its chemical composition and crystal structure. Two stones can look identical to the eye but be entirely different minerals. Here are the most commonly encountered gemstone species and their key distinguishing properties:
| Gemstone | Mineral Species | Hardness | Key Visual Property | Common Look-Alike |
|---|---|---|---|---|
| Ruby | Corundum (Al₂O₃) | 9 Mohs | Vivid red; strong UV fluorescence in natural stones | Red spinel, red garnet |
| Sapphire | Corundum (Al₂O₃) | 9 Mohs | All colours except red; blue most common | Blue topaz, aquamarine, tanzanite |
| Emerald | Beryl (Be₃Al₂Si₆O₁₈) | 7.5–8 Mohs | Deep green; characteristic jardin inclusions | Green tourmaline, peridot, green glass |
| Aquamarine | Beryl (Be₃Al₂Si₆O₁₈) | 7.5–8 Mohs | Pale blue-green; high clarity typical | Blue topaz, pale sapphire, blue glass |
| Topaz | Topaz (Al₂SiO₄(F,OH)₂) | 8 Mohs | Perfect basal cleavage; imperial orange-pink is rarest | Citrine, quartz, aquamarine |
| Tourmaline | Complex borosilicate | 7–7.5 Mohs | Strong pleochroism; striated prism faces | Emerald, ruby, sapphire (by colour) |
| Garnet | Silicate group (varies) | 6.5–7.5 Mohs | High refractive index; no cleavage; 12-faced crystals | Ruby, spinel, zircon |
| Opal | Hydrated silica (SiO₂·nH₂O) | 5.5–6.5 Mohs | Play of colour unique to opal — no other gem replicates it | Synthetic opal, opal doublets/triplets |
| Amethyst | Quartz (SiO₂) | 7 Mohs | Purple; hexagonal prism habit; colour zoning common | Purple fluorite, iolite, kunzite |
| Spinel | Magnesium Aluminate | 8 Mohs | Singly refractive; octahedral crystals; vivid colours | Ruby (red spinel), sapphire (blue spinel) |
| Tanzanite | Zoisite (Ca₂Al₃Si₃O₁₂(OH)) | 6.5–7 Mohs | Strong trichroism — blue, violet, and burgundy depending on angle | Blue sapphire, iolite, synthetic glass |
| Peridot | Olivine (Mg₂SiO₄) | 6.5–7 Mohs | Distinctive olive-green; doubling of facets visible under loupe | Green tourmaline, demantoid garnet |
“Colour is the most misleading single property in gemstone identification. A red stone could be ruby, spinel, garnet, tourmaline, or glass. The AI examines luster, crystal habit, transparency, and optical behaviour together — never colour alone.”
Natural, Synthetic, and Simulant Gemstones — What’s the Difference?
These three categories are distinct and the difference matters enormously for value. Understanding them helps you interpret your result correctly.
How Our AI Flags Synthetic and Treated Stones
Several visual cues in photographs suggest synthetic or treated origin. Our AI looks for these specifically:
- Unusual clarity. Natural gemstones almost always contain inclusions. A perfectly clean stone of large size in a precious colour should raise scrutiny — it may be synthetic or heavily treated.
- Colour zoning patterns. Natural stones show irregular, geological colour zoning. Synthetic stones often show curved growth lines or unusually regular colour distribution.
- Too-vivid colour. Colour enhancement through heat treatment, irradiation, or beryllium diffusion can produce unnaturally saturated colours — particularly in sapphires and topaz.
- Surface features. Fracture-filled stones (common in emeralds and rubies) sometimes show iridescent “flash” along fracture planes, visible in good photographs.
Treatment disclosure requirement
Most gemstones on the market are treated in some way — heat treatment, oiling, fracture filling, and coating are all common. Reputable sellers are required to disclose treatments. For significant purchases, always ask for treatment disclosure in writing and verify with a gemological laboratory certificate.
How to Photograph Gemstones for Best Results
Gemstones present unique photographic challenges because of their high refractive index, strong brilliance, and small size. These four tips make a significant difference to identification accuracy:
For stones in jewellery settings
Mounted stones are harder to photograph clearly because the setting obscures the girdle and pavilion. Try to photograph the crown straight-on through the table facet, and include a close-up showing the setting’s metal hallmarks if visible. The hallmarks can tell you the metal type and sometimes the era, which provides useful context about likely stone quality.
Why Colour Alone Never Identifies a Gemstone
The single most common mistake in gemstone identification is over-relying on colour. Almost every colour occurs in multiple gemstone species, and the same species can occur in almost every colour. Here are the most frequently confused colour groups:
- Red stones: Ruby, red spinel, red garnet (pyrope, almandine), rubellite tourmaline, red glass, synthetic ruby, red zircon. Ruby is statistically the rarest of these — most red stones are garnet or spinel.
- Blue stones: Sapphire, blue topaz, aquamarine, tanzanite, iolite, blue tourmaline, London blue topaz, synthetic spinel, blue glass. Blue topaz and aquamarine are frequently confused even by experienced jewellers.
- Green stones: Emerald, green tourmaline, tsavorite garnet, demantoid garnet, peridot, green sapphire, chrome diopside, malachite (opaque), green glass. Fine emerald is rarer than the other green alternatives.
- Purple stones: Amethyst, purple sapphire, iolite, purple fluorite, kunzite, sugilite, tanzanite in certain lighting. Purple fluorite is the most common misidentification for amethyst.
- Yellow/orange stones: Citrine, yellow topaz, yellow sapphire, yellow tourmaline, hessonite garnet, golden beryl, spessartine garnet. Heated amethyst is frequently sold as citrine.
“When a customer brings in a ‘ruby’, experienced gemologists assume it is probably garnet or spinel until proven otherwise — because fine natural rubies are genuinely rare, and the look-alikes are everywhere.”
Frequently Asked Questions
Still Have a Question?
Use the tool above to identify your specific gemstone — or explore our specialist identifier tools for individual gem types.
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