The facts
What spinel actually is
Spinel is classified as spinel, with the composition MgAl₂O₄. It crystallises in the cubic system.
Colour comes from chromium for red, cobalt for the rare blue, iron for grey, which is also what a laboratory looks at when it is asked whether a colour is natural.
Refractive index 1.712–1.736. Specific gravity around 3.58–3.61. Cleavage: none. Those three numbers separate it from most of what imitates it.
Where spinel comes from
Spinel is produced at Mogok, Myanmar, Luc Yen, Vietnam, Mahenge, Tanzania, Sri Lanka and Tajikistan (Kuh-i-Lal).
The locality is part of the description, not a footnote — two stones of the same weight from two of these places are not the same stone.
How spinel is treated
Usually untreated, which is one of its arguments against ruby. Some heating exists.
Treatment changes value, sometimes by a multiple, so it belongs in the description before the price and not after the sale.
What spinel is confused with
In the trade spinel is most often mistaken for, or substituted by, Ruby, Garnet or Synthetic spinel — very common in old jewellery.
The separation is rarely a matter of opinion: refractive index 1.712–1.736 and specific gravity 3.58–3.61 settle most of it in a minute, and magnification settles the rest.
What spinel is used for
Demand for spinel comes from jewellery, mineral collecting and watch dials, which is why one price per carat never covers it.
We quote each application in the unit that trade actually buys in, by the carat, by the specimen or by the disc.
Durability and care
Hardness 8; cleavage none. 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 spinel costs
As a guide, spinel trades around $100–20,000/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 spinel treated, and how?
Usually untreated, which is one of its arguments against ruby. Some heating exists.
Where does spinel come from?
Mogok, Myanmar, Luc Yen, Vietnam, Mahenge, Tanzania, Sri Lanka and Tajikistan (Kuh-i-Lal). Origin affects price, so we name the locality rather than the country on every quote.
Is spinel hard enough to wear every day?
Yes. At 8 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 spinel cost?
Indicatively $100–20,000/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 spinel confused with?
Most often Ruby, Garnet and Synthetic spinel — very common in old jewellery. A refractive index of 1.712–1.736 and a specific gravity near 3.58–3.61 separate it quickly.
What is spinel used for besides jewellery?
mineral collecting and watch dials. Each of those trades buys it in a different form and a different unit.
Related stones
Looking for spinel?
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 spinel