KhyatiGems knowledge library
Spinel
Spinel is distinct from corundum, even though red spinel and ruby can look similar. Red, pink, blue and other colours occur.
AI-assisted source review · 2026-10-16. No named gemologist review is claimed. How this reference was reviewed.
Robert M. Lavinsky · CC BY-SA 3.0 · Source · CC BY-SA 3.0
| Material classification | Spinel |
|---|---|
| Mohs hardness (reference) | 8 |
Identity and appearance
Spinel is distinct from corundum, even though red spinel and ruby can look similar. Red, pink, blue and other colours occur.
A historic association with ruby does not make spinel a ruby variety. Laboratory-grown spinel also exists; material and formation must be stated separately.
Care and handling
Assess the actual stone for fractures and treatment before cleaning. A family name alone cannot describe its condition.
Questions for an individual stone
Keep the material name, natural or laboratory-grown origin, treatment description and any report together. Ask which conclusions were established by examination and which remain unknown. The reference properties here describe a material; they are not measurements of a stone offered for sale.
If a description and report disagree, request clarification before making a decision. Photographs are useful for discussing appearance, but cannot authenticate a specimen. Keep care instructions with the item so that a jeweller or repairer can assess it before work begins.
Comparison and interpretation
A useful comparison is red spinel and ruby. Their similar appearance explains why a clear material identification matters, but modern descriptions should not merge them into one mineral. Another comparison is natural and laboratory-grown spinel: a shared mineral name is different from a conclusion about formation. Ask which of those questions the report addresses. A colour photograph, including a very vivid one, is not an identification record. Check that the photographed object, measurements and report details can be matched without relying only on a familiar colour.
Choosing and documenting a piece
Assess colour under more than one ordinary light and ask about the actual condition of the stone. Visible inclusions or a chipped edge may affect a setting decision independently of the mineral name. Spinel hardness does not eliminate the need to protect an exposed gem. For an existing piece, inspect the mounting as well as the stone before cleaning. If an advertised origin or treatment claim is important to your decision, retain the supporting conclusion in writing and distinguish it from the seller’s general description of the material.
Before making a decision
For spinel, ask the seller to identify the actual item, state what remains unknown and explain the scope of any report. Keep photographs, measurements and written disclosures together. If an answer matters to your decision, obtain it before commissioning a setting or arranging a repair.
Sources and further reading
- GIA Spinel reference Checked 2026-10-16