Synthetic Sapphire: identification, value, and how to spot a fake

Quick facts

Mineral family

corundum (synthetic)

Chemical formula

Al2O3

Mohs hardness

9

Refractive index

1.762–1.77

Specific gravity

3.97–4.05

Crystal system

trigonal

Luster

vitreous

Colors

Synthetic Sapphire is found in any. The body color, its saturation, and how evenly it spreads through the stone are among the strongest drivers of value.

How to tell real from imitation

No single test settles it, but a few grounded checks quickly narrow things down for Synthetic Sapphire. Hardness, brilliance, and the list of stones it is commonly confused with all give you something concrete to look for.

• Scratch resistance: genuine Synthetic Sapphire sits at Mohs 9, so it should resist scratching from softer materials — a stone that mars far too easily is suspect.
• Brilliance & luster: Synthetic Sapphire shows a vitreous luster and a refractive index of 1.762–1.77; imitations often look glassier or flatter under the same light.
• Density: a real Synthetic Sapphire has a specific gravity near 3.97–4.05, so it feels heavier or lighter in the hand than many look-alikes of the same size.
• Fast first read: photograph the stone in the Jewelry Identifier app to estimate the gemstone and its likely value range, then confirm anything important with a gemological lab.

Common treatments

• lattice diffusion

Treatments are routine for many Synthetic Sapphire stones, but they materially affect value and should always be disclosed — an untreated, lab-certified stone commands a clear premium over a treated one.

What to know about Synthetic Sapphire

Synthetic corundum produced by flame fusion (Verneuil), flux growth, or hydrothermal. Physically identical to natural sapphire. Must be disclosed as 'synthetic' or 'lab-created' per FTC.

Sources

• Wikidata Q4118