Arrangement of Minerals, 17© 



Genus IV. Calc-Spar. 

 Rhomboliedral. Prismatic. IIarclness=3.0 — 4.5. Sp. gr.=2.5 — 3.2. 

 * Common Calc-Spars, and Limestones. 

 1. Prismatic Calc-Spar or Aragonite. 2. Rliombohedral Calc-Spar or 

 Common Calc-Spar. 



** Magnesian Calc-Spars^ and Limestones. 

 .3. Dolomite Calc-Spar. 4. Magnesite Calc-Spar, 6. Ankerite Calc- 

 Spar. 



Genus V. Fluor. 

 Tessular. Hardness = 4. Sp. gr. = 3.144. 

 1. Octahedral or common Fluor Spar. 



Genus VI. Apatite. 

 Rhomboliedral. Hardness = 5.0. Sp. gr. = 3.225. 

 1. Rhombohedral Apatite or common Phosphate of Lime. 



ft 

 Genus VII. Alumstone. 



Rhombohedral. Cleavage axotomous. Hardness = 3.5 — 4.0. 

 Sp. gr. =2.5—2.8. 



1. Rhombohedral Alumstone. (Alumine souS'Sulphatie Alcaline, 

 Haliy.) 



+ + t 

 Genus VIII. Wavellite. 

 Prismatic. Cleavage perfect in oblique directions. Hardness 

 = 3.5 — 4.0. Sp. gr. = 2.3 — 2.4. 



1. Prismatic Wavellite or Phosphate of Alumina. 



tttt 

 Genus IX. Cryolite. 

 Prismatic. Cleavage in three rectangular directions. Hardness 

 = 2.5 — 3.0. Sp. gr. =: 2.9 — 3.0. 



1. Prismatic Cryolite (Alumne Fluat^e Alcaline. HaUy). 



Order II. BARALLITE.— 7/e«r^ Saline Minerals. 

 Not metallic. Streak white. Hardness = 3.0 -—4.0. Sp. 

 gr. = 3.6 — 4.7. 



Genus I. Heavy-Spar. 

 Prismatic. Hemiprismatic. Hardness = 3.0 — 4.0. Sp. gr. = 3.6 

 — 4.7. 



* Barytic Spars. 

 1, Baryto-Calcitc or Hemiprismatic Heavy-Spar. 2. Witherite, or 

 Diprismatic Heavy-Spar {Carbonate of Barytes). 3. Common 

 Heavy-Spar, or Prismatic Heavy-Spar {Sulphate of Barytes). 



