The facts
What gedrite actually is
Mineralogically, gedrite is amphibole group (orthoamphibole) — ☐Mg₂(Mg₃Al₂)(Si₆Al₂)O₂₂(OH)₂, crystallising in the orthorhombic system.
The colour is caused by fe²⁺ gives the brown to grey-green; iridescence in nuummite comes from oriented exsolution lamellae between gedrite and anthophyllite. That is worth knowing because it determines what heating, light and time can and cannot do to the stone.
A refractometer reads 1.625–1.718, and the specific gravity sits near 3.15–3.26; cleavage is perfect prismatic in two directions.
Where gedrite comes from
The recognised sources are Gèdre, Hautes-Pyrénées, France, Nuuk, Sermersooq, Greenland and Simiuttat, Greenland.
Origin affects price in this material, so we name the locality on every quote rather than the country. "African" or "Asian" tells a buyer nothing.
How gedrite is treated
Untreated; nuummite cabochons are sometimes given a resin topcoat to brighten the iridescence. Avoid dry grinding of fibrous varieties.
None of this is a problem when it is said out loud. It becomes one the moment it is left out.
What gedrite is confused with
The usual confusions are Anthophyllite, Nuummite and Astrophyllite.
The separation is rarely a matter of opinion: refractive index 1.625–1.718 and specific gravity 3.15–3.26 settle most of it in a minute, and magnification settles the rest.
What gedrite is used for
Gedrite is bought by mineral collecting and jewellery — and each of those trades wants a different form of the same material.
We quote each application in the unit that trade actually buys in, by the specimen or by the carat.
Durability and care
Gedrite is 5.5–6 on the Mohs scale, with perfect prismatic in two directions cleavage.
Hardness is not the whole story. Perfect cleavage means the stone can split cleanly if struck along the wrong plane, whatever its Mohs number, so a protective setting matters more here than the hardness suggests.
Warm water, mild soap and a soft brush. Avoid ultrasonic cleaners on anything fracture-filled, stabilised, dyed or visibly included.
What gedrite costs
Indicative pricing for gedrite is Nuummite-type cabochons 20–120 USD.
That is a range, not a quote. Colour, size, clarity, cut and origin move the figure a long way inside it, and the only honest price is one given against a specific stone. Send us what you need and we will price it.
Questions
Is gedrite treated, and how?
Untreated; nuummite cabochons are sometimes given a resin topcoat to brighten the iridescence. Avoid dry grinding of fibrous varieties.
Where does gedrite come from?
Gèdre, Hautes-Pyrénées, France, Nuuk, Sermersooq, Greenland and Simiuttat, Greenland. Origin affects price, so we name the locality rather than the country on every quote.
Is gedrite hard enough to wear every day?
With care. It is 5.5–6 on the Mohs scale, which is hard enough, but perfect prismatic in two directions cleavage means it can split if struck at the wrong angle. Use a protective setting and avoid ultrasonic cleaning.
How much does gedrite cost?
Indicatively Nuummite-type cabochons 20–120 USD. Colour, size, clarity and origin move the price a long way within that, so treat it as a range and ask for a quote against a specific stone.
What is gedrite confused with?
Most often Anthophyllite, Nuummite and Astrophyllite. A refractive index of 1.625–1.718 and a specific gravity near 3.15–3.26 separate it quickly.
Related stones
Looking for gedrite?
Tell us the size, the quality and what it is for. We source it, photograph it and quote it — with the locality named.
Ask about gedrite