Science

Apollonius’ theorem is an elementary geometry theorem relating the length of a median of a triangle to the lengths of its sides. It states that “the sum…

Dawsonite is a mineral composed of sodium aluminum carbonate hydroxide, chemical formula NaAlCO3(OH)2. It is an orthorhombic mineral composed of sodium aluminum carbonate hydroxide. It…

Daubréelite is a rare sulfide mineral. It crystallizes with cubic symmetry and has a chemical composition of Fe2+Cr3+2S4. It is a mineral consisting of a…

Daubréeite is a rare bismuth oxohalide mineral with formula BiO(OH, Cl). It is a sulphide of chromium observed in some meteoric irons. It is a…

Datolite is a calcium boron hydroxide nesosilicate, CaBSiO4(OH). It is a popular mineral among mineral collectors although it is somewhat obscure. It was first observed…

Danburite is a calcium boron silicate mineral with a chemical formula of CaB2(SiO4)2. It is a mineral consisting of a calcium borosilicate that is transparent…

Danalite is an iron beryllium silicate sulfide mineral with formula: Fe2+4Be3(SiO4)3S. It is beryllium-bearing, and found typically in tin-beryllium skarns, but also found in NYF…

Coltan (short for columbite–tantalites and known industrially as tantalite) is a dull black metallic ore from which the elements niobium and tantalum are extracted. The…

Clinochrysotile is a soft, fibrous silicate mineral in the serpentine group of phyllosilicates, also called “white asbestos”. It is a monoclinic form of Chrysotile. It…

Cleveite is an impure radioactive variety of uraninite containing uranium and found in Norway. It has the composition UO2 with about 10% of the uranium…

Citrine is a variety of quartz whose color ranges from a pale yellow to brown due to ferric impurities. It is a glassy yellow variety…

Chrysoprase is a gemstone variety of chalcedony that contains small quantities of nickel. It is an apple-green gemstone consisting of a variety of chalcedony that…