Mineralogy. 181 



zerland: No. 4. a granular black variety, from Hall in Tyrol. As the 

 mineral contains no lime, it cannot be placed under the genus lime-ha- 

 loide. Professor Stromeyer called it Magnesite-spar. — Gottinger gelehrte 

 Anzeigen, No. 158, 1827. 



25. Chrysolite in the Cavities of Obsidian. — Professor Gustavus Rose of 

 Berlin has found in the cavities of Obsidian, in the Jacal Rock near Real- 

 del-Monte in Mexico, little crystals, greenish, and reddish-yellow, and 

 transparent, which belong to the species of prismatic Chrysolite. — Pog- 

 gendorff's Annalen, Vol. x. p. 323. 



26. N'ew Minerals. — Professor Breithaupt (Schweigger's Journal der 

 Chemie und Physik, N. S. Vol. xx. p. 314, &c. gives a description of the 

 following new mineral species : 



I. Karphosiderite, Name derived from the straw-yellow colour. Re- 

 niform masses, rarely from granular composition, uneven ; shining and 

 glimmering in the streak, with resinous lustre. Colour and streak pale 

 and high straw-yellow. Hardness = 4.0 ... 4.5. Sp. Gr. = 2.5. Feels 

 greasy. Before the blowpipe upon the coal it becomes black and melts in 

 a strong fire into a globule, which is attractible by the magnet. In glass 

 of borax it is easily soluble, and with salt of phosphorus it melts into a 

 black scoria. It contains oxide of iron, phosphoric acid, water, with small 

 quantities of oxide of manganese and zinc. It has a great similarity to 

 oxalite, yellow iron-ore, or iron-sinter. It occurs in Greenland. 



II. Mesitine-spar. Name derived from fxiTitmiy that is, what stands 

 in the middle (of brachytypous lime-haloide, and brachytypous parachrose 

 baryte.) Rhombohedral, R — cc. R =. 107° 14' R + oo. Cleavage dis- 

 tinct, parallel to R. Lustre vitreous. Colour dark-greyish, and yellowish- 

 white... yellowish-grey. Streak white. Transparent... translucent. Hard- 

 ness =4. Sp. Gr. = 3.34...3.37. Before the blowpipe the mesitine-spar 

 decrepitates. In muriatic and nitric acid a feeble effervescence takes 

 place, but it is entirely soluble. It contains probably magnesia, lime, pro- 

 toxide of iron, and oxide of manganese. It is found in little crystals, in 

 rhombohedral quartz at Traversella in Piemont. 



III. Tautolite, Prismatic. Fundamental form, scalene four-sided 

 pyramid. 



aib'^c —I: 1.9451: 1.3648. 

 Observed combinations : 



1, ilf r= CO a : 6 : c = 109^ 46'. 

 ^ = 4 a : Z> : ao c = 51° 52'. 



A = Gc a: <x> b : c Fig. 9 of Mobs treatise, 2, M; g; h; 

 i=z ^ a: I b : c = 36° 22'. ) ^^^ p, . ttt !?;«. a 



Cleavage, only in traces and interrupted, parallel to Mand h. Fracture 

 conchoidal... uneven. Lustre vitreous. Colour velvet-black. Streak grey. 

 Opaque. Hardness = 6.5. ..7.0. Sp. Gr. = 3.865. Before the blowpipe, 

 upon charcoal, the tautolite melts to a blackish scoria, which is attracted 

 by the magnet ; with borax it melts to a clear green glass. These and 

 other reactions show that the mineral consists of silica, black protoxide of 



