Orthorhombic; usually massive or granular. G = 4·9. H = 5-6. Brown to red; translucent to opaque. Ryddarhyttan, Sweden; Batoum, Caucasus? _Chalcolamprite._ A silico-columbate of E, Zr, Ca, Fe, Na, K; R₂Cb₂F₂SiO₉, where R represents various metals. E = 3·41; ZrO₂ = 5·7%. Cubic, in small octahedra. G = 3·77. H = 5¹⁄₂. Greenish brown; opaque. Metallic lustre (χαλκός = Copper, λαμπρός = lustre). Narsarsuk, S. Greenland. _Churchite._ Hydrous phosphate of Cerium metals and Ca; Cer = 51·87%. Monoclinic? Allegations only. G = 3·14. H = 3¹⁄₂. Greyish; transparent to translucent. Cornwall. _Cleveite._ A variety of Uraninite (_q.v._) rich in rare earths and helium. Cer = 2·3-2·9; Yttr = 10·0-10·3; ThO₂ = 4·6-4·8%. Cubic; usually massive. G = 7·49. H = 5¹⁄₂. Black; opaque. Arendal, Norway. ~Cordylite.~ Fluocarbonate of Cerium metals and Ba; E₂F₂Ba(CO₃)₃. Cer = 49·4%. Hexagonal; isomorphous with Parisite (_q.v._). G = 4·31. H = 4¹⁄₂. Yellow; transparent. Plain of Narsarsuk, Greenland. Cossyrite. A variety of Aenigmatite (_q.v._) of very complex composition, TiO₂ = 6-8%. Anorthic. G = 3·74. H = 5. Black; opaque. Island of Pantellaria (formerly Cossyra). _Cyrtolite._ A pseudomorph after zircon, allied to Alvite (_q.v._). Tetragonal. _See_ Alvite. Various localities in Scandinavia, and U.S.A. _Davidite._ A Titanate of Fe, U, V, Cr, and E--uncertain formula. TiO₂ > 50; E₂O₃ = 5-10%. Cubic--in grains and rounded crystals. G = 4 about. Black, with brilliant lustre. Olary, S. Australia. ~Delorenzite.~ 2FeO,UO₂,2Y₂O₃,24TiO₂. Yttr = 14·63; TiO₂ = 55%. Rhombic; habit prismatic. G = 4·7. H = 5¹⁄₂-6. Black; translucent to opaque; lustrous. Craveggia, Piedmont, Italy. Derbylite. FeO,Sb₂O₅ + 5FeO,TiO₂? TiO₂ = 35% about. Orthorhombic; habit prismatic. G = 4·53. H = 5. Pitch black; opaque; lustre resinous. Tripuhy, Minas Geraes, Brazil. Dysanalyte (Perovskite). Approximately 6RTiO₃,R(Cb,Ta)₂O₆, where R = Ca, Fe´´. Believed by Hauser to be merely an impure Perovskite (_q.v._). Cer = 0-5·1; TiO₂ = 41·5-59·3%. Cubic. G = 4·13. H = 5-6. Black; opaque. Vogtsburg, near Baden, Germany. Elpidite. Na₂Zr(Si₂O₅)₃, 1¹⁄₂H₂O. ZrO₂ = 20·5%. Orthorhombic. G = 2·52-2·56. H = 7-8. Colourless to red; translucent. Various localities in Greenland. _Endeiolite._ R´´Cb₂O₆(OH)₂ + R´´SiO₃ (cf. Chalcolamprite). E₂O₃ = 4·43; ZrO₂ = 3·78%. Cubic. G = 3·44. H = 4. Dark chocolate-brown; transparent. Narsarsuk, Greenland. _Erdmannite_ (Michaelsonite). A silicate of E and Ca, with Zr, Be, Th, Al, Fe, aq., etc. An altered Homilite? Cer = 17·7-34·9; Yttr = 1·4-2·1; ThO₂ + ZrO₂ = 0-12%. Amorphous; isotropic. G = 3·01-3·39. H = 4¹⁄₂. Brown to leek-green. Near Brevig, Norway. _Erikite._ A phosphosilicate of E, Ca, Al, K and Na, with ThO₂, H₂O, etc. Cer = 40·5; ThO₂ = 3·3%. Orthorhombic.