CaratThe trade's price book bends to ruby
GemGuide pushed Mozambique ruby prices sharply higher and scrapped its ten-point scale for Burma stones, pricing only four grades — an admission that fine ruby is now too scarce to chart the usual way.
When the reference book changes shape, the market has already moved. GemGuide, the pricing service the American colored-stone trade leans on, has revised its ruby charts: Mozambique prices raised sharply on strong demand for unenhanced, untreated material, and the Burma section rebuilt from the ground up.
Ruby is quietly running the colored-stone story diamonds used to own — a scarce natural material getting scarcer, priced by origin and honesty rather than size. When the guide stops grading a stone the old way, it is telling you the supply, not the demand, is the thing that broke.
| Figure | |
|---|---|
| Upper Extra Fine | Grade 10 |
| Upper Fine | Grade 8 |
| Lower Good | Grade 5 |
| Middle Commercial | Grade 3 |
IThe book changes shape
Research director Stuart Robertson said Mozambique prices have, in effect, skyrocketed as tender buyers chase clean goods.
The Burma change is the more striking admission. GemGuide abandoned its traditional one-to-ten quality scale for unenhanced Burmese ruby and now publishes just four grades — Middle Commercial, Lower Good, Upper Fine and Upper Extra Fine — leaving users to interpolate the rest.
The reason is scarcity: fine Mogok material has become so hard to source that availability now matters more than price. You cannot chart a stone that does not come to market.
IIToo scarce to grade
Mozambique has carried the category for over a decade, and its tenders — Gemfields' chief among them — now set the global reference for gem and near-gem ruby.
That is where the price pressure is coming from: a single dominant source, buyers competing for untreated goods, and a treatment-disclosure culture that has taught the trade to pay a real premium for stones that have not seen the furnace.
IIIOrigin over size
The revisions go live in the service's app immediately and reach print in the July–August issue.
For appraisers and retailers that means the number under a ruby changed this week whether or not the stone did — the kind of quiet repricing that ripples through insurance values and estate valuations long after the tender room empties.
01Method · the desk’s arithmetic+
The only four grades GemGuide now prices for unenhanced Burma ruby.
02Sources1 document
Emeralds hold at $146 a carat; rubies wait their turn
Gemfields' emeralds hold their price.
The trade, filed before the New York open.
Prices, tenders and the one story that moved the industry overnight. Ninety seconds.
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