366 STRONTIANOCALCITE. 



granular masses. Colour pale asparagus- 

 green, or apple-green; also white, yellow, 

 grey, or brown. Transparent to translucent. 

 Lustre shining, pearly. Yields easily to the 

 knife. Streak white. Brittle. Fracture 

 uneven. H. 3-5 to 4. S.G. 3-6 to 3-71. 



Comp. Carbonate of strontia, or SrC = 



strontia 70-27, carbonic acid 29-73 = 100. 



Analysis from Strontian, by Thomson : 



Carbonate of strontia . 93*43 



Carbonate of lime . . 6-28 



Protoxide of iron . . 0-01 



99-72 



BB fuses at the edges, then rapidly swells 

 up and forms a cauliflower-like mass, which 

 becomes highly incandescent, imparting a 

 reddish colour to the flame, and giving an 

 alkaline reaction. 



Effervesces in nitric and muriatic acids. 



Soluble in 18,045 parts of pure water at 

 ordinary temperatures, and in 1536 parts of 

 boiling water. 



Localities. — English. Yorkshire ; Pately 

 Bridge and Nidderdale, in snow-white 

 translucent crystals.j^^r. 416. — Scotch. Stron- 

 tian, in Argyleshire, sometimes as in Jig. 417, 

 but generally in acicular, diverging groups. 

 — Foreign. I3raunsdorf, in Saxony. Hamm, 

 Westphalia. The Harz. Leogang, in Salz- 

 burg. United States, at Schoharie, &c. 



Name. After the locality, Strontian, Avhere 

 it was first found. 



Brit. Mus., Case 41. 



M. P. G. Horse-shoe Case,Nos. 275 to 278. 



Dr. Hope first discovered the earth Stron- 

 tian in this mineral, and named it after the 

 locality where the specimens had been ob- 

 tained. 



Stkontianocalcite, Genth. A variety 

 of Calcite containing strontia. 



Strontites, Allan, Hope, Phillips. See 

 Stroktianite. 



Struveite, Dufrenoy. Struvite, Ulex. 

 Occurs in regular six-sided prisms, with 

 dihedral terminations. Primary form a right 

 rhombic prism. Colour pale yellow, and 



Fig. 418. 



sometimes transparent, but generally ren- 

 dered black and opaque by the interposition 

 of organic matter. Lustre vitreous. Brittle. 

 Tasteless, and very slightly soluble in water. 

 H. 2. S.G. 1-7. 



SUBSESQUICHROMATE. 



Comp. Phosphate of magnesia and am- 

 monia, or Mg P + NH^O + 13H = phosphoric 

 acid 29-9, magnesia 16-3, ammonia 1G"6, 

 water 44-0 = 100. 



Analysis, by Ulex : 



Phosphoric acid . . . 28*56 

 Magnesia .... 13'46 

 Protoxide of iron . . , 3*06 

 Protoxide of manganese . 1-12 

 Ammonia and water . . 53-76 



99-96 



BB falls to powder, giving ofi' water and 

 ammonia, and fuses to a colourless glass 

 which, when cool, forms a Avhite enamel. 



Readily soluble in acids. 



Locality. Saldanha Bay, on the coast of 

 Africa, in guano. 



Numerous crystals, some of which were 

 from an inch to an inch and a quarter long, 

 and a quarter of an inch thick, were found, 

 in 1845, in digrging the foundations of the 

 church of St. Nicholas, at Hamburg. The 

 soil in which they occurred was a bed of 

 peat or turf, formed by the putrefaction of 

 organic matter (stable "^litter), and the rub- 

 bish from an old chateau, which was de- 

 stroyed by fire in 1072. The same salt 

 exists in certain animal secretions, and is 

 deposited from decomposing urine. 



Name. After the Russian Councillor of 

 State, von Struve. 



Brit. Mus., Case 60 A. 



Stygmite. a beautiful variegated variet}- 

 of Carnelian, of a reddish-yellow or yellow- 

 ish-red coloiir, traversed by numerous white 

 lines. 



Stylobate. (From a-TvXeQa.7'/ii, the foot 

 of a column.) See Gehlenite. 



Stypticite. The fibrous form of yellow 

 copperas {Copiapite). 



Comp. 2FeS2 + 21H. 



Analysis, by H. Rose : 



Sulphuric acid . . .31*73 



Peroxide of iron . , . 2811 



Silica 1-43 



Magnesia .... 059 



Lime 1-91 



Water 36-56 



100*53 



SuBFLUATE OF Cerium, PMlUps. See 

 Fluocerine. 



SuBPHosPHATE OF Alumina. See 

 Wavellite. 



SUBSESQUICHROMATE OF LeAD, Thom," 



son. See Melanochroite. 



