Cristobalite 1.50 Ct El Hoyazo
40,00€
Gem: Cristobalite
Weight: 1.50 Cts.
Size: 7.5 x 5.3 x 4.4 mm.
Origin: Níjar (Spain)
Treatments: None
Clarity: VVS1 Very very small inclusions
Misc: In the La Hoya deposit in Níjar (a volcanic crater), we can find various minerals, including Almandine/Andradite garnets (“Granatillas”) and Cristobalites. It’s very difficult to find any of gem quality suitable for cutting, but occasionally a few appear, and it’s a true pleasure to facet these rare and unique gems. For this occasion, I designed this “Silene” cut, a very elaborate one that gives this precious gem an extra sparkle.
Gemological certificate included: with a photo of the rough crystal and the cutting diagram.
Cristobalite — A volcanic gem
Cristobalite is a mineral polymorph of silica that is formed at very high temperatures. It can form as a secondary mineral of volcanic rocks, such as in devitrification processes. It has the same chemical formula as quartz, SiO₂, but a distinct crystal structure. Both quartz and cristobalite are polymorphs with all the members of the quartz group, which also include coesite, tridymite and stishovite. It is named after Cerro San Cristóbal in Pachuca Municipality, Hidalgo, Mexico.
El Hoyazo (Níjar, Almería, Spain) is the crater of an ancient submarine volcano formed around 10 million years ago. After the volcano became inactive, coral reefs developed along the crater rim—now preserved as fossils. Erosion and sea-level changes have kept this geological structure remarkably well preserved.
Inside the crater you can find a variety of minerals and crystals such as sillimanite, biotite, cordierite, cristobalite and garnets. These crystals come from ancient, deep rocks that the rising magma incorporated and carried to the surface.
You can find High-quality cristobalite from El Hoyazo. Some crystals show exceptional transparency, ranging from a few millimeters up to 10 cm once cut, it can display an excellent crystal appearance.
If you’re not completely satisfied, you can return the gemstone
In stock