The group
One mineral, six trade names, and a price range of four orders of magnitude. Goshenite — pure, colourless beryl — is worth a few dollars a carat. Red beryl from Utah reaches twenty thousand. The difference is a trace element measured in parts per million.
Emerald is the commercial centre of the family and the one with a treatment convention all of its own: it is characteristically fractured, and filling those fractures with oil or resin has been standard practice for centuries. The grade of filling — none, minor, moderate, significant — is what a laboratory reports, and it moves the price substantially.
Aquamarine is routinely heated to drive off a yellow component and leave pure blue. The change is permanent and undetectable, so assume it. Morganite is often heated for the same reason.
All beryls share a weakness worth knowing: imperfect cleavage in one direction, and in emerald's case a fracture-prone habit. Never put a beryl in an ultrasonic cleaner, and never steam-clean an oiled emerald — the filling comes out and the stone looks suddenly much worse.
Every beryl compared
The whole group side by side. Where the constants overlap, the species cannot be named from a refractometer alone — which is exactly why the trade names mislead.
| Variety | Species | Colour | Mohs | RI | SG | Guide price |
|---|---|---|---|---|---|---|
| Alexandrite | Chrysoberyl | green | 8.5 | 1.745–1.759 | 3.70–3.78 | $2,000–70,000/ct |
| Aquamarine | Beryl | teal | 7.5–8 | 1.577–1.583 | 2.68–2.74 | $30–500/ct |
| Bertrandite | Beryllium silicate | colourless | 6–7 | 1.583–1.614 | 2.59–2.60 | Specimens 20–200 USD; faceted stones 200–800 USD/ct |
| Beryl | Beryl | green | 7.5–8 | 1.562–1.602 | 2.66–2.90 | Common beryl 5–50 USD/ct; fine emerald above 20,000 USD/ct |
| Beryllonite | Beryllonite | colourless | 5.5–6 | 1.552–1.562 | 2.80–2.85 | Faceted stones $50–$250/ct; fine Pakistani crystals $100–$3,000 |
| Cat's Eye Aquamarine | Beryl | blue | 7.5–8 | 1.577–1.583 | 2.68–2.72 | 30–300 USD/ct |
| Cat’s eye chrysoberyl | Chrysoberyl | yellow | 8.5 | 1.745–1.759 | 3.70–3.78 | $200–10,000/ct |
| Chrysoberyl | Chrysoberyl | yellow | 8.5 | 1.745–1.759 | 3.70–3.78 | $50–800/ct |
| Emerald | Beryl | green | 7.5–8 | 1.577–1.583 | 2.67–2.78 | $300–30,000/ct |
| Goshenite | Beryl | colourless | 7.5–8 | 1.577–1.583 | 2.66–2.72 | $10–60/ct |
| Heliodor | Beryl | yellow | 7.5–8 | 1.577–1.583 | 2.68–2.74 | $20–200/ct |
| Hurlbutite | Beryllium phosphate | colourless | 6 | 1.595–1.604 | 2.88–2.92 | Faceted stones 150–600 USD/ct |
| Maxixe Beryl | Beryl | blue | 7.5–8 | 1.578–1.584 | 2.68–2.80 | Low and unstable — fades; not a commercial gem |
| Morganite | Beryl | pink | 7.5–8 | 1.577–1.583 | 2.71–2.90 | $20–300/ct |
| Pezzottaite | Pezzottaite (beryl group) | pink | 7.5–8 | 1.601–1.620 | 3.09–3.11 | $300–3,000/ct |
| Red Beryl | Beryl | red | 7.5–8 | 1.564–1.574 | 2.66–2.70 | $2,000–20,000/ct; clean stones over 1 ct exceptional |
| Tiffany Stone | Beryllium-bearing opalised fluorite breccia | violet | 4–6 | 1.43–1.54 (variable, spot) | 2.4–2.8 | Rough 40–200 USD/kg; cabochons 25–150 USD |
| Trapiche Emerald | Beryl | green | 7.5–8 | 1.577–1.583 | 2.67–2.78 | $100–3,000/ct depending on pattern sharpness |
Questions
Are emeralds oiled?
Nearly all of them. Emerald grows fractured, and filling those fractures with oil or resin is centuries-old accepted practice. What matters is the grade — none, minor, moderate or significant — and whether it is disclosed. Filling can dry out or be stripped by careless cleaning.
Is aquamarine heated?
Almost always, to remove a yellow-green component and leave a purer blue. The change is permanent and cannot be detected, so the trade prices aquamarine on the assumption that it has been heated.
What is the rarest beryl?
Red beryl, sometimes called bixbite, from the Wah Wah Mountains in Utah — effectively the only gem source on earth. Fine stones reach $5,000 to $20,000 per carat and are almost always under one carat.
Can I wear an emerald every day?
With care. Hardness of 7.5 to 8 is fine, but emerald is characteristically fractured and usually oiled. Avoid ultrasonic and steam cleaning entirely, and choose a protective setting.
Looking for beryl?
Tell us which variety, what size and what it is for. We source it, photograph it and quote it, with the locality named.
Ask about beryl