Gemstone Nqe Lus
Yuav cov khoom ntuj tsim hauv peb lub khw
Amblygonite name comes from Greek “crooked angled”, referring to mineral’s triclinic crystals. It is a fluorophosphate mineral, (Li,Na)AlPO4(F,OH). The chemical compition is lithium, also sodium, aluminium, phosphate, fluoride and hydroxide. The mineral occurs in pegmatite deposits. We can confuse it with albite or feldspars. Its density, cleavage and flame test for lithium are diagnostic. It s forms a series with montebrasite, the low fluorine endmember. Geologic occurrence is in granite pegmatites, high-temperature tin veins, and also greisens. It occurs with spodumene, apatite, lepidolite, tourmaline, and other lithium-bearing minerals in pegmatite veins. It contains about 10% lithium. It’s also a source of lithium for industry. The chief commercial sources have historically been the deposits of California and France.
Transparent amblygonite is now in gemstone classification. As a gemstone set into jewelry it is vulnerable to breakage and abrasion from general wear, because its hardness and toughness are poor. The main sources for gem material are Brazil and also United States. We can found quality specimens in Australia, also in France, Germany, Namibia, Norway and Spain.
Amblygonite cim npe
Refractive Index: 1.578 rau 1.646
Optical Character: Biaxial/+, –
Birefringence: 0.020 rau 0.030
Density: 2.98 – 3.11, Average = 3.04
Crystal System: Triclinic
Lus: vitreous, pearly
Dispersion: 0.014 rau 0.015
The mineral was discovered in Saxony, by August Breithaupt in 1817. He named this stone from the Greek amblus, blunt, and gonia, angle. Because of the obtuse angle between the cleavages. Later it was found at Montebras, Creuse, France, and at Hebron in Maine; and because of slight differences in optical character and chemical composition the names montebrasite and hebronite have been applied to the mineral from these localities. It has been discovered in considerable quantity at Pala in San Diego county, California; also Caceres, Spain; and another to the Black Hills of South Dakota. The largest documented single crystal of amblygonite measured 7.62×2.44×1.83 m3 and finally weighed 102 tons.