Diamonds are approximately 3.3 billion years old. Diamonds are transported from Earth's mantle to surface. Some meteorites contain diamonds over 5 billion years old
Alabaster is a soft mineral used for carving and plaster production. Two main types: fine-grained gypsum and banded calcite. Gypsum alabaster is soft (Mohs 1.5-2), calcite harder (Mohs 3). Both types are translucent and slightly soluble in water
Corundum is crystalline aluminum oxide containing iron, titanium, vanadium, and chromium. Naturally transparent, color varies with transition metal impurities. Crystallizes with trigonal symmetry in R3c space group. Has hardness of 9.0 on Mohs scale, can scratch most minerals
Soapstone is a metamorphic rock composed mainly of magnesium-rich talc. Forms through dynamothermal metamorphism in subduction zones. Contains varying amounts of chlorite, amphiboles, and minor iron-chromium oxides. Pure steatite is 63.37% silica, 31.88% magnesia, and 4.74% water
Natural stones are typically made of quartz, such as novaculite from Arkansas. Belgian Coticule and Blue stones are highly valued for their natural beauty. Japanese stones (tennen toishi) are traditionally used with water. Natural stones have been used since antiquity, as documented by Pliny
Jadeite is the rarer and harder variety of jade, belonging to the pyroxene group. Jadeite typically occurs as a sodium-aluminum silicate rock with polycrystalline structure. Jadeite is highly durable and resistant to household dust