Other rare gems
This collection presents mostly « rare gems » or « collector gems », more often not used in jewellery because of rarity or hardness. . Rarity is due to the quantity available, or a rare color, source or inclusion, or the difficulty to cut the rough into a faceted gem. Microphotographies are taken with an old Olympus microscope and an iphone. These gems are not for sale, but some extra specimens may be available. The collection is visible but stored in a specific location, so please contact me for an appointment.
Some of these gems are exceedinly rare as faceted gems as the milarite from St-Gottard, the proustite, the kämmererite or the spurrite. Some other great rarities are present as taaffeite, grandidierite, roselite or cancrinite.
Kämmererite is a rare variety of Clinochlore containing chromium. the stone is micaceous and has a perfect basalt clivage, it is extremely difficult to facet and such faceted gems are terribly rare and almost never found on the market. It presents « horsetail » type inclusions.
Rough: © Etsy
Phosphophyllite is one of the rarest mineral on earth and gem crystals comes only from the Unificada Mine in Potosí, Bolivia. Facetting is hard because of the perfect cleavage. This small specimen has a pale bluish color far from the good bluish green.
Rough: © Worthpoint
Grandidierite is a classic rare gem from Andrahomana, South Madagascar. This specimen’s color is a bit light but clarity is good for the specie.
Spurrite is a rare silicate found in different color, extremely scarse as faceted gem. The best source for the purple variety is the Fuka Mine,Takahashi City, Okayama Prefecture in Japan. They are only a view faceted specimens on the market. The metallic inclusion is to be magnetite. This gem has a quite strong color shift.
Rough: © Dakotamatrix
Alexandrite is the most famous variety of Chrysoberyl. It contains chrome, display a spectacular pleochroism and the most famous color change. This stone is extremely sought after, even more the Russian one. Both stones come from Sri Lanka. This very very tiny stone display a beautiful pleochroism and a honest color change, for a good clarity. The second stone has a cat’s eye effect.
This colorless topaz also named « Rainbow topaz » (not the chemically coated mystic topaz!) has needle iridescent inclusions. As they are numerous and oriented they reproduce an effect of chatoyancy. From Brazil.
Usually Kyanite doesn’t present chatoyancy. This stone present not a cat’s eye but a star, which is even rarer!
Kunzite is a variety of spodumene and normally never present asterism. The cat’s eye is difficult to see but present, and very rare on that specie.
Extremely rare sugilite « gel » (translucent). Only half of sugilite material has the best purple color, and 0,1% of this purple material is translucent. Wessels Mine, South Africa. The gem has a very strong color shift from dark purplr to pinkish!w
Rough: © Bonhams
A pyromorphite from China, a leas mineral. Very good color and transparency and quite scarce as faceted gem.
Rough: © Dakotamatrix
A purple Taaffeite from the classic deposit Ratnapura, Sri Lanka, with a color shift from dark to pinkish purple. Considered as one of the rarest gems, Taaffeite is very close to Spinel but double-refractive, so this one was tested by a laboratory.
Lizardite is usually yellowish green. This rare variety comes from Wessels Mine in South-Africa, and get’s it’s color from Hematite.
Rough: © E-rocks auctions
Extremely rare proustite from Peru. Hardness is 2 so extremely hard to cut because if the softness. This silver arsenic sulphide tends to react to light and become black. This gem is very well preserved. A great rarity.
Rough: © crystaclassics.co.uk
Crocoite is a rare lead mineral, very rare as faceted gem because of the very low hadness. This well cut specimen comes from Tanzania. With polarized light the pleochroism is clearly visible.
Rough: Mindat Juergen Merz
Cancrinite is extremely rare as faceted gem. This one is to come from RUssia and has wonderful two phase inclusions.
Roselite is extremely scarse because crystals are extremely small. This one has a very good color and comes from Abu Azzer, Morocco.
Rough: © mcdouglasminerals
Milarite is very scarce as faceted, this one is a great rarity as it comes from the type source, Mt St-Gothard, Switzerland. Almost impossible to find on the market.
Rough: © The Arkenstone
Scorodite is extremely rare as faceted gem. This gem comes from Tsumeb mine, Oshikoto region, Namibia. Pleochroism is quite strong from blue to purple and some rare specimen can change collor under different light sources, as this one, from blue to green.
Rough: © Heritage auction
A chrome diopside comming from Merelani, Arusha region Tanzania. Color intensity, clarity and size are exceptionnal for this source.