DIOPSIDE BACCILLAIRE. 

 Analysis, from Fassa, by Wacktnroder : 



Lime 24-74 



Magnesia . . . • . 18-22 

 Protoxide of manganese . 0-18 

 Protoxide of iron . . . 2*50 



Silica 45-16 



Alumina . . . .0-20 



100-00 



BB alone fuses to a colourless, almost 

 transparent glass. 



Localities. In translucent crystals, in 

 veins traversing Serpentine at Ala, in Pied- 

 mont, accompanied by Epidote, Hyacinth, 

 red Garnet, and green Talc. The more 

 transparent crystals from this locality are 

 sometimes cut and worn as gems. 



N"me. From Itk, through, and c-^'?, ap- 

 pearance ; in allusion to its occasional trans- 

 parency. 



Brit. Mus., Case 34. 



31. P. G. Horse-shoe Case, No. 1033. 



DiOPSiDE BACCILLAIRE, Dufrenoy. See 

 MussiTK, Breislakitb. 



DlopsioE COMPACTE, Dufrenoy. See 

 Shekzolite, Karlibinite. 



DioPSiDEGRANULiFORME, Dufrenoy. See 



COCCOLITE, FUNKITE. 



DiOPTASE, Hady, Nicol, Dana. Silicate 

 of Copper. Hexagonal. Colour emerald- 

 green. Lustre vitreous. Transparent to 

 translucent Streak green. Brittle. Fracture 

 conchoidal. H. 5. S.G. 3-27 to 3-34. 



Fig. 165* 



Comp. Silicate of copper or Cu^ Si^-i-SH 



= silica, 38-3, oxide of 



copper 50-3, water 



114 = 100-0. 





Analysis by Hess : 





Oxide of copper . 



. 45-10 



Silica . 



. 36-85 



Alumina 



. 2-36 



Lime . 



. 3-39 



Magnesia 



. 0-22 



Water . 



. 11-52 



99-44 

 BB decrepitates, tinging the flame yel- 

 lowish green; becomes black in the outer 

 —red in the inner flame, but does not fuse. 

 With borax fuses to a green, globule, and is 

 finally reduced. 



Dissolves in heated nitric or muriatic acid, 

 ■with the formation of a jelly of silica. 



DIPRISMATIC LEAD BAEYT. 115 



Localities, This scarce mineral occurs 

 disposed on Quartz in small but well- 

 defined crystals, at Altyn Tiibe, in the 

 Kirghese steppes of Siberia. It is also found 

 between Oberlahnstein and Braubach in the 

 Duchy of Nassau. 



Name. From ^toTToiMxi, to see through, in. 

 allusion to the natural joints being visible 

 by transmitted light. 



It may be distinguished from Emerald by 

 inferior hardness, higher specific gravity, 

 and by becoming negatively electric by 

 friction. 



Brit. Mus., Case 26. 



DioxYLiTE, Shepard. See Lanarkite. 

 DiPHANiTE, Nordenskiold. A mineral 

 allied to Margarite, found in the emerald 

 mines of the Uralian mountains, together 

 with Emerald, Cymophane, and Phenakite, 

 on a brown micaceous slate. It forms regu- 

 lar six-sided prisms with a perfect cleavage 

 at right angles to the principal axes. The 

 crystals appear blue and transparent on o.ae 

 side, and have a vitreous lustre ; but on the 

 cleavage-faces the mineral appears white 

 and opaque when in tolerably thick laminae, 

 and has a mother-of-pearl lustre. Very 

 brittle. H. 5 to 5-5. S.G. 3-04 to 3-07. 



Comp. 2(K2 Si) + 3A12 Si) + 4H. 



Analysis by Jewreinow : 



Lime 13-11 



Protoxide of iron . . 3-02 

 Protoxide of manganese . 1-05 

 Alumina .... 43-33 



Silica 34-02 * 



Water 5-34 



99-87 

 BB becomes opaque, swells up, exfoli- 

 ates, and fuses in the inner flame to a 

 smooth enamel, with borax and microcos- 

 mic salt, readily yields a clear glass which 

 becomes yellowish on cooling ; whence the 

 name Diphanite — from ^h double, and <?«nif, 

 appearance. 



DiPLOGENIC KOUPHONE SpAE, Mohs. 



See Epistilbite. 



DiPLoiTE, Breithaupt. A variety of 

 Anorthite. See Latrobite. 



Diprismatic Copper Glance, Mohs. 

 See Bournonite. 



Diprismatic Euclas Haloid, Haidin- 

 ger. See Haidingerite. 



Diprismatic Ikon Ore, Mohs. See 



LiCORITE. 



Diprismatic Hal Bakyt. Mohs. See 



WiTHEKITE. 



Diprismatic Lead Baryt, Mohs. See 

 Cerusite. 



i2 



