What is your gemstone worth?
Coloured stones do not price like diamonds. There is no universal grading standard, and treatment usually matters more than size — two rubies that look identical can differ in value by thousands of times.
Your stone
Origin only adds value when a recognised laboratory has certified it. A seller's claim on its own is worth nothing.
Priced by size, not by carat
Value climbs steeply with diameter — large round pearls are disproportionately rare.
Your pearls
Measure across a single pearl. Quality is mostly lustre — a fine pearl reflects a sharp image, a poor one looks chalky.
Treatment matters more than anything else
This is the single most important thing to understand about coloured stones, and the thing most owners do not know about their own. A lead-glass filled ruby and an untreated Burmese one can look alike across a counter and differ in value by a factor of thousands. Glass filling is not a minor enhancement — such a stone is substantially glass by volume, and ordinary jeweller's heat during a repair can destroy it.
Heating, by contrast, is routine, permanent and accepted. Assume any ruby or sapphire is heated unless a laboratory report says otherwise. Nearly every emerald is oiled; minor oil is normal, and only moderate or significant filling meaningfully reduces value.
Why these ranges are wider than a diamond's
Diamonds have the 4Cs and a single dominant grading authority. Coloured stones have neither. Colour quality — the thing that drives most of the value — is judged by eye, and two respected labs can describe the same stone differently. Any honest coloured stone estimate is therefore a broader range than a diamond estimate, and ours are.
When a report is worth paying for
If the calculator suggests your stone might be worth more than roughly $2,000, a laboratory report on treatment and origin will usually pay for itself several times over. Without one a buyer must assume the least favourable case and will price for that risk. How we work these figures out.
What each stone is worth
Value per stone type, and why treatment moves the number more than size does.