What black opal costs, from someone who buys the rough
Last reviewed
Four variables, in the order that actually matters
Body tone first. An N1–N2 stone and an N6 stone of identical brightness are not in the same price bracket and are not the same product, whatever the listing calls both of them.
Brightness second — graded loosely from brilliant down to dull, and the fastest way to lose money is to buy a dark body tone with a dead face because the N-number looked good.
Pattern third: harlequin, then broad flash, then rolling flash and the rest, with pinfire at the bottom. Color within the pattern is part of this — red is worth a multiple of green at the same brightness.
Size last. Most sellers list size first because it is the only one of the four they can measure with a tool rather than an eye. A 3ct stone with a dull face is worth less than a 1ct stone with a live one, every time.
Per-carat bands for solid Australian black opal
These are the bands I work with when I'm buying and pricing. They are wide because opal is genuinely priced per stone rather than per carat — two stones at the same weight and tone can sit at either end of a band depending on how the face behaves in the hand. Use them to sanity-check a price, not to value a specific stone.
| Stone | Per carat (USD) |
|---|---|
| Dark opal, N5–N6, modest color | $30 – $150 |
| Black opal, N1–N4, modest color or small | $150 – $600 |
| Black opal, N1–N4, bright, good pattern | $600 – $3,000 |
| Gem black opal, N1–N2, broad flash, strong red | $3,000 – $15,000+ |
| Doublet (thin opal on a glued backing) | priced per piece, tens to low hundreds |
| Triplet (opal slice under a dome) | priced per piece, tens of dollars |
What a finished ring or pendant lands at
Take the stone price, then add metal and labour. Sterling adds relatively little; 14k gold adds real money and rises with the gold price. Hand-setting a cabochon in a bezel built for that one stone is a half-day of skilled work, not a mount pulled from a drawer.
In practice: a small dark-opal pendant in sterling can be a few hundred dollars all-in. A one-carat bright black opal ring in 14k is a four-figure object before anyone has been greedy. A gem-grade stone set properly is a five-figure ring, and the stone is most of the number.
That is also why you should be suspicious of a cheap setting under an expensive stone. If a seller has spent thousands on rough and then set it in a cast mount, ask why.
Why the rough market sets the floor
I buy parcels before I know what is in them. A parcel of Lightning Ridge rough is priced on what it might contain, and what it actually contains is discovered on the wheel, sometimes badly. Some stones come out better than the price paid. Plenty come out as potch with a hint of color and go in the box of things that weren't.
That risk is real money and it is priced into every finished piece anyone sells. It is also the honest answer to "why is opal expensive when you cut it yourself" — cutting it myself is what lets me tell you exactly what you're holding, not a discount mechanism.
The arithmetic check anyone can run
Cheap plus big plus vivid equals composite, treated, or lab. There is no fifth option. A "2ct black opal ring" at $150 has to be a doublet, a triplet, a smoked or dyed stone, or grown in a factory, because the rough alone would cost more than the asking price.
What each of those should cost instead: a triplet, tens of dollars. A doublet, tens to a couple of hundred. Lab-created opal, very little. Treated material, priced as treated and labelled as such. All of them are fine products sold honestly — the fraud is never the doublet, it's the missing word. More on the tells in how to tell if an opal is real and solid opal vs. doublets and triplets.
This page gets refreshed
Opal prices move with the rough market, the gold price and the exchange rate, and a price guide that never changes is a price guide nobody is checking. I review these bands once a year and stamp the date at the top of this page when I do.
Common questions
- How much is black opal per carat?
- Solid Australian black opal runs roughly $150–$600 per carat for N1–N4 stones with modest color, $600–$3,000 for bright stones with good pattern, and $3,000 to well over $15,000 per carat for gem-grade broad flash with strong red on an N1–N2 body. Dark opal (N5–N6) sits below that at roughly $30–$150.
- Why is black opal so expensive?
- Nearly all of it comes from one small field in New South Wales, most of what is mined is potch with no play of color, and the rough is bought on risk before anyone knows what is inside it. Rarity plus that risk sets the floor before cutting, metal and setting are added.
- Is a $150 black opal ring real?
- Not as solid stone. Rough black opal costs more than that before it is cut, so a finished ring at that price is a doublet, a triplet, a treated stone or lab-created. Those are legitimate products — the problem is only when the word 'solid' goes missing from the listing.
- Does carat weight decide an opal's price?
- Less than any other variable. Body tone, brightness and pattern come first; size comes last. A one-carat stone with a live face beats a three-carat stone with a dull one every time.
Keep reading