Oxide minerals

What this family is

Oxygen as the principal anion is the mineralogical criterion, which sets corundum beside chrysoberyl: ruby and the sapphire colours on one branch, alexandrite and cat's-eye chrysoberyl on the other; spinel (MgAl₂O₄, including cobalt spinel) belongs here too.

Internationally the unqualified term cat's-eye is reserved for chrysoberyl. Beryllium-diffused sapphire and flux-healed ruby remain corundum, with the treatment disclosed. Kashmir and Ceylon are origin claims, not guarantees.

Scope of this family

Minerals with oxygen as the principal anion, classified mineralogically as oxides.

Representative members (28)

The standard materials in this family: mineral species, varieties, rocks and other materials whose name identifies what they are. Trade names are listed separately below.

Common confusions

Names in this family that do not by themselves say what the material is, and man-made or assembled products recorded against its materials. Each line says what the item actually is.

Trade names in this family

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Name	Type of name	What it actually is
Beryllium-Diffused Sapphire	Trade name: colour / appearance variety	Sapphire treated by lattice diffusion of beryllium to produce colour that runs through the whole stone; the treatment must be disclosed at sale.
Burma Ruby	Trade name: geographic / origin-linked name	A Ruby trade name historically associated with the mines of Myanmar (Burma); it is not a separate mineral species and is not in itself proof of origin.
Ceylon Sapphire	Trade name: geographic / origin-linked name	A trade name for sapphire historically associated with Sri Lankan sources; not a separate mineral species and no guarantee of origin.
Flux-Healed Ruby	Trade name: colour / appearance variety	Ruby whose fractures have been healed by heat treatment with a flux; residual flux is not a natural inclusion and must be disclosed.
Kashmir Sapphire	Trade name: geographic / origin-linked name	A trade name for Sapphire linked to the historic deposits of Kashmir; it is not a separate mineral species and does not guarantee origin.
Lead-Glass-Filled Ruby	Trade name: colour / appearance variety	Ruby whose fractures or cavities are filled with lead glass. Sources differ: lab reports still describe it as natural corundum treated by filling, US marketing may not call it unqualified “ruby” or “treated ruby”, and the Chinese national standard names it as a treated gem.

Synthetic, assembled or treated counterparts

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Name	Counterpart of	What it actually is
Synthetic Chrysoberyl	Chrysoberyl	Synthetically made chrysoberyl; GB/T 16552-2017 Annex A Table A.4 lists it as "synthetic chrysoberyl", and its synthetic nature must be disclosed up front.
Synthetic Corundum	Corundum	Synthetically made corundum; GB/T 16552-2017 Annex A Table A.4 lists it as "synthetic corundum", and the name must disclose its synthetic nature up front.
Synthetic Ruby	Ruby	Synthetically made red corundum, the counterpart of natural Ruby; GB/T 16552-2017 Annex A Table A.4 lists it as "synthetic ruby".
Synthetic Sapphire	Sapphire	Synthetically made corundum, the counterpart of natural Sapphire; GB/T 16552-2017 Annex A Table A.4 lists it as "synthetic sapphire", with the colour stated separately.
Synthetic Spinel	Spinel	Synthetically made Spinel; GB/T 16552-2017 Annex A Table A.4 lists it as "synthetic spinel". It is often used to imitate other gems.

Member entries (34)

Market names not to be used as a product name

Recorded on member entries of this family. Each name links to the entry whose page explains the ruling and its source.

All misleading and prohibited trade names across the site: Misleading and prohibited trade names

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Market name	Recorded on	Status
alexandrite sapphire	Colour-change Sapphire	Not to be used in any position

Treatments recorded on member entries

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Treatment	Member entries	Disclosure requirement
Heated / Heat-treated	Beryllium-Diffused Sapphire, Burma Ruby, Ceylon Sapphire, Colour-change Sapphire, Corundum, Flux-Healed Ruby, Green Sapphire, Kashmir Sapphire, Padparadscha Sapphire, Pink Sapphire, Purple Sapphire, Ruby, Sapphire, Star Ruby, Star Sapphire, Yellow Sapphire	Heating is a common treatment, and acceptance varies by material. Whether heated ruby or sapphire must be declared separately depends on which code is followed (see the comparison on this page); unstable colour or foreign residues must be disclosed.
Filled / Fracture-filled	Beryllium-Diffused Sapphire, Burma Ruby, Ceylon Sapphire, Colour-change Sapphire, Corundum, Flux-Healed Ruby, Green Sapphire, Kashmir Sapphire, Lead-Glass-Filled Ruby, Padparadscha Sapphire, Pink Sapphire, Purple Sapphire, Ruby, Sapphire, Spinel, Star Ruby, Star Sapphire, Yellow Sapphire	Name the filler (resin, oil, polymer, glass or lead glass) and bear in mind that fillings can be unstable and may deteriorate or change colour over time. LMHC Information Sheet #3 treats corundum with glass in two ways: glass in fissures or cavities is still reported on natural corundum as a filling, and only a badly fractured single piece infused throughout, or small fragments bound together with glass, is reported as a manufactured product.
Diffusion-treated	Beryllium-Diffused Sapphire, Burma Ruby, Ceylon Sapphire, Colour-change Sapphire, Corundum, Flux-Healed Ruby, Green Sapphire, Kashmir Sapphire, Padparadscha Sapphire, Pink Sapphire, Purple Sapphire, Ruby, Sapphire, Spinel, Star Ruby, Star Sapphire, Yellow Sapphire	Must be disclosed. Surface diffusion produces colour only in a thin layer that repolishing can remove; bulk diffusion is permanent but still requires disclosure.
Irradiated	Beryllium-Diffused Sapphire, Cat’s-eye, Cat’s-eye Chrysoberyl, Ceylon Sapphire, Colour-change Sapphire, Corundum, Green Sapphire, Kashmir Sapphire, Padparadscha Sapphire, Pink Sapphire, Purple Sapphire, Sapphire, Star Sapphire, Yellow Sapphire	Must be disclosed. Stability under irradiation varies by material: irradiated blue topaz keeps a stable colour and irradiated smoky quartz or coloured diamond can, but in some materials the irradiated colour fades in light or heat; colour stability must be pointed out.
Dyed	Beryllium-Diffused Sapphire, Burma Ruby, Ceylon Sapphire, Colour-change Sapphire, Corundum, Flux-Healed Ruby, Green Sapphire, Kashmir Sapphire, Padparadscha Sapphire, Pink Sapphire, Purple Sapphire, Ruby, Sapphire, Spinel, Star Ruby, Star Sapphire, Yellow Sapphire	Must be disclosed. Dye may fade, bleed or dissolve in solvents (alcohol, acetone), and dyed material must not be labelled "natural colour"; dyed jadeite counts as B/C jade and must be conspicuously labelled; dyed agate and chalcedony are extremely common.

Care codes on member entries

Member entries cite these CIBJO special-care codes: special-care code b, special-care code g, special-care code h, special-care code j, special-care code k, special-care code l, special-care code m. General gem care gives the full wording of every code.

Where members are recorded

Some member entries record the localities where their materials are found; Recorded localities shows them on a sketch map and lists them by continent.

Names

简体中文: 氧化物矿物
繁體中文: 氧化物礦物
English: Oxide minerals
日本語: 酸化鉱物

Authority source

Authority source

Review status

Reviewed against CIBJO, GB/T and IMA boundaries.

Distribution across the other axes

All 34 members share these values:

Origin class: Natural materials
Material domain: Natural inorganic gem materials
Mineral chemical class: Oxides / hydroxides

Identity level

Construction or treatment status

Natural identity; treatment status unknown (27)
Natural; common industry optimization (verify with certificate) (6)
Natural; treatment common (require certificate to distinguish) (1)