The facts
What star Ruby actually is
Mineralogically, star Ruby is corundum — Al₂O₃, crystallising in the trigonal system.
The colour is caused by cr³⁺; the six-rayed star is reflection from oriented rutile exsolution needles. That is worth knowing because it determines what heating, light and time can and cannot do to the stone.
A refractometer reads 1.762–1.770 (spot ~1.76), and the specific gravity sits near 3.97–4.05; cleavage is none; parting.
Where star Ruby comes from
The recognised sources are Mogok, Myanmar, Ratnapura and Elahera, Sri Lanka and Chimwadzulu Hill, Malawi.
Origin affects price in this material, so we name the locality on every quote rather than the country. "African" or "Asian" tells a buyer nothing.
How star Ruby is treated
Diffusion-induced asterism exists and is a serious trap: titanium diffusion creates a synthetic silk layer near the surface. Many 'star rubies' in the trade are synthetic Linde or glass-filled. Genuine stones may still be gently heated.
None of this is a problem when it is said out loud. It becomes one the moment it is left out.
What star Ruby is confused with
The usual confusions are Synthetic Linde star ruby, Diffusion-treated corundum and Star garnet.
The separation is rarely a matter of opinion: refractive index 1.762–1.770 (spot ~1.76) and specific gravity 3.97–4.05 settle most of it in a minute, and magnification settles the rest.
What star Ruby is used for
Star Ruby is bought by jewellery and mineral collecting — and each of those trades wants a different form of the same material.
We quote each application in the unit that trade actually buys in, by the carat or by the specimen.
Durability and care
Hardness 9; cleavage none; parting. That combination decides what it can safely be set into.
With no cleavage plane to worry about, the practical limit is abrasion rather than breakage, and it takes daily wear well.
Warm water, mild soap and a soft brush. Avoid ultrasonic cleaners on anything fracture-filled, stabilised, dyed or visibly included.
What star Ruby costs
Indicative pricing for star Ruby is Opaque commercial $20–$150/ct; fine translucent Burmese $2,000–$20,000/ct.
That is a range, not a quote. Colour, size, clarity, cut and origin move the figure a long way inside it, and the only honest price is one given against a specific stone. Send us what you need and we will price it.
Questions
Is star Ruby treated, and how?
Diffusion-induced asterism exists and is a serious trap: titanium diffusion creates a synthetic silk layer near the surface. Many 'star rubies' in the trade are synthetic Linde or glass-filled. Genuine stones may still be gently heated.
Where does star Ruby come from?
Mogok, Myanmar, Ratnapura and Elahera, Sri Lanka and Chimwadzulu Hill, Malawi. Origin affects price, so we name the locality rather than the country on every quote.
Is star Ruby hard enough to wear every day?
Yes. At 9 on the Mohs scale with no cleavage plane, it handles daily wear well. The practical limit is gradual abrasion rather than chipping.
How much does star Ruby cost?
Indicatively Opaque commercial $20–$150/ct; fine translucent Burmese $2,000–$20,000/ct. Colour, size, clarity and origin move the price a long way within that, so treat it as a range and ask for a quote against a specific stone.
What is star Ruby confused with?
Most often Synthetic Linde star ruby, Diffusion-treated corundum and Star garnet. A refractive index of 1.762–1.770 (spot ~1.76) and a specific gravity near 3.97–4.05 separate it quickly.
Related stones
Looking for star ruby?
Tell us the size, the quality and what it is for. We source it, photograph it and quote it — with the locality named.
Ask about star ruby