Features reported for this material
Spinel
OCTAHEDRA — two four-sided pyramids base to base — often sharp and glassy, sometimes twinned flat as 'spinel twins'. The single most useful habit in rough identification, because corundum never does it.
cubic
Red, hot pink, orange, grey, blue, violet, black. Frequently arrives clean and well formed.
The drawing is a octahedron. Two four-sided pyramids joined base to base. Corundum never does this, which makes it one of the few shapes that settles an argument on its own. Compare it with what is in your hand as a prompt for better photographs, not as an identification. Waterwear, damage and incomplete growth can remove the expected form.
Editorial status: specialist review pending
Evidence record for this page
The links are editorial source targets, not certificates for a submitted stone. The page remains noindex until a named specialist checks the entry claim by claim.
- Handbook of Mineralogy, Mineralogical Society of America — mineral identity, crystal system, habit, physical properties, recorded localities.
- GIA Gem Encyclopedia and Gems & Gemology research — gem-variety terminology, trade context, reported sources, treatment context.
- GIA introduction to gem treatments — treatment categories, limits of visual treatment assessment, disclosure context.
- CIBJO Coloured Stone Commission, Official Gemstone Book — accepted nomenclature, artificial-product terminology, treatment disclosure terminology.
Author: pending · Specialist reviewer: pending · Review date: pending · Next review: pending
What it gets mistaken for
Spinel is reported as being confused with ruby, garnet, taaffeite and synthetic spinel. Photographs cannot resolve many of those alternatives. If you are not certain, say so and preserve the name you were originally given as a seller claim.
Where it comes from
Reported producing localities in this working reference include Tanzania, Sri Lanka, Vietnam, Tajikistan, Madagascar, Myanmar. This is not proof that a stone came from one of them, and it does not mean an approved purchase route exists there.
Treatment
Generally untreated, which is a real selling point.
Tell us what has been done to it, if you know, and distinguish what you know first-hand from what somebody told you. Media cannot establish treatment. Any acceptance policy and laboratory requirement is decided for the case.
How to photograph it
Daylight, on a plain white surface, and, only if the material is safe to wet, photograph the same material dry and briefly wet. This can reveal different apparent surface and internal features without proving identity, quality or value. Put a ruler or another clearly identified scale reference in the frame. The full guide is here.