The group
The word garnet on a label tells you almost nothing about price. A commercial almandine and a fine tsavorite are both garnets, and one costs a thousand times the other. What matters is which species, and after that the colour.
The family splits into two series that do not mix freely. The pyralspite series — pyrope, almandine, spessartine — shares aluminium in the Y site. The ugrandite series — uvarovite, grossular, andradite — shares calcium in the X site. Most stones on the market are intermediate compositions rather than end members, which is why the constants overlap and why a refractometer alone often will not name the species.
Two things are true of all of them and are worth knowing before you buy: garnets are never heated, oiled or irradiated as a trade practice, so there is no treatment to disclose; and none of them have a cleavage plane, which makes the whole family unusually safe to set and to wear.
Every garnet 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 |
|---|---|---|---|---|---|---|
| Almandine | Almandine garnet | red | 7–7.5 | 1.78–1.83 | 3.95–4.30 | $5–80/ct |
| Andradite | Garnet group | green | 6.5–7 | 1.880–1.940 | 3.70–4.10 | Yellow and black material 5–40 USD/ct; Russian demantoid with horsetails 1,000–8,000 USD/ct |
| Chrome Pyrope | Garnet group (pyrope) | red | 7–7.5 | 1.740–1.760 | 3.65–3.80 | 10–80 USD/ct; small sizes dominate |
| Colour-change garnet | Pyrope–spessartine garnet | violet | 7–7.5 | 1.74–1.76 | 3.80–3.95 | $200–3,000/ct |
| Coticule | A metamorphic rock in which 5-20 micrometre spessartine garnet crystals are dispersed through a mica-rich phyllite matrix - a natural garnet abrasive in a self-releasing binder | yellow | Garnet 7-7.5 in a matrix around 3-4 - the softness of the binder is what makes it work | 1.79-1.81 (spessartine) | 2.70-2.90 | $80-350 for a small bout or rubbing stone; $200-900 for a full-size vein-identified bench coticule |
| Demantoid | Andradite garnet | green | 6.5–7 | 1.880–1.889 | 3.82–3.85 | $500–10,000/ct |
| Eclogite | A high-pressure metamorphic rock of red pyrope-almandine garnet in green omphacite pyroxene, formed in subduction zones | red | 6-7.5 | 1.67-1.79 (mixed) | 3.30-3.60 - unusually heavy, which is diagnostic in the hand | $10-80 per kilogram for ornamental slabs; diamond-bearing xenoliths from named kimberlites $200-5,000 per specimen |
| Gadolinium Gallium Garnet | Synthetic garnet-structure oxide | colourless | 6.5–7 | 1.970 | 7.02–7.09 | 5–40 USD/ct |
| Garnet (Industrial Abrasive) | Crushed and graded almandine or andradite garnet, used as a cutting and blasting abrasive because it fractures to fresh sharp edges and is low in free silica | red | 7-8 | 1.77-1.83 (almandine) | 3.90-4.30 | Approximately $170 per tonne average US import unit value (USGS, 2025); bagged waterjet grades $300-600 per tonne retail |
| Grossular | Grossular (garnet group) | green | 7–7.5 | 1.730–1.760 | 3.55–3.73 | $10–300/ct depending on variety |
| Hessonite | Grossular garnet | orange | 7–7.5 | 1.73–1.75 | 3.57–3.73 | $10–100/ct |
| Hydrogrossular | Grossular–hibschite series (garnet group) | green | 6–7 | 1.700–1.730 (spot ~1.72) | 3.15–3.55 | $0.50–15/ct |
| Leuco Garnet | Grossular (garnet group) | colourless | 7–7.5 | 1.730–1.745 | 3.55–3.65 | $10–80/ct |
| Malaia garnet | Pyrope–spessartine garnet | orange | 7–7.5 | 1.74–1.76 | 3.78–3.94 | $50–500/ct |
| Mali Garnet | Grossular–andradite (garnet group) | yellow | 6.5–7 | 1.760–1.790 | 3.64–3.87 | $50–400/ct |
| Melanite | Andradite (garnet group) | black | 6.5–7 | 1.855–1.895 | 3.70–3.90 | $5–50/ct |
| Mint Garnet | Grossular (garnet group) | green | 7–7.5 | 1.734–1.745 | 3.57–3.67 | $40–400/ct |
| Pyrope | Pyrope garnet | red | 7–7.5 | 1.72–1.76 | 3.65–3.87 | $10–150/ct |
| Rainbow Garnet | Garnet group (andradite) | green | 6.5–7 | 1.880–1.940 | 3.80–3.90 | 50–600 USD/ct for well-oriented Japanese material |
| Rhodolite | Pyrope–almandine garnet | pink | 7–7.5 | 1.74–1.77 | 3.74–3.94 | $20–200/ct |
| Schorlomite | Garnet group | black | 7–7.5 | 1.940–1.980 | 3.77–3.93 | Beads and cabochons 5–40 USD |
| Spessartite | Spessartine (garnet group) | orange | 7–7.5 | 1.79–1.81 (published ranges differ with composition — see the page) | 4.12–4.20 | $25–3,000/ct by colour, clarity and origin |
| Star Garnet | Garnet group (almandine) | red | 7–7.5 | 1.790 (spot) | 4.05–4.20 | 20–200 USD/ct; sharp Idaho four-ray stones at the top of that range |
| Topazolite | Andradite (garnet group) | yellow | 6.5–7 | 1.875–1.895 | 3.80–3.90 | $50–500/ct for clean faceted stones |
| Tsavorite | Grossular garnet | green | 7–7.5 | 1.734–1.745 | 3.57–3.65 | $300–5,000/ct |
| Umbalite | Garnet group (pyrope-spessartine) | pink | 7–7.5 | 1.750–1.765 | 3.78–3.85 | 20–150 USD/ct |
| Uvarovite | Uvarovite (garnet group) | green | 6.5–7 | 1.860–1.870 | 3.71–3.81 | Drusy plates by the piece; faceted material rare and priced by negotiation |
| Yttrium Aluminium Garnet | Synthetic garnet-structure oxide | colourless | 8–8.5 | 1.833 | 4.50–4.60 | 2–20 USD/ct |
Questions
Are garnets always red?
No. Red is only the best-known colour. Tsavorite and demantoid are green, spessartite is orange, rhodolite is pink-purple, and colour-change garnet shifts between daylight and incandescent light. The only colour the family does not produce naturally is a pure blue.
Are garnets treated?
Essentially never. Garnets are not heated, oiled, irradiated or diffused as a trade practice, which makes them one of the few gem families with nothing to disclose. Fracture filling exists but is rare and would be a defect, not a norm.
Which garnet is the most valuable?
Demantoid and tsavorite lead, both green and both reaching several thousand dollars per carat in fine quality. Fine spessartite follows. Almandine and pyrope, the common reds, sit in the tens of dollars per carat.
Is garnet hard enough for a ring?
Yes. The family runs 6.5 to 7.5 on the Mohs scale with no cleavage plane, which makes garnet one of the more practical coloured stones for daily wear.
Looking for garnet?
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 garnet