Sample page from Classified List of Species, 

 Geo. L. English & Co.'s Catalogue of Minerals. 



3. HELVITE GROUP. Isometric, Tetrahedral. 



366. Helvite; isometric; H=6-6.5; G=3. 16-3.36; orthosilicate of mangan- 



ese, beryllium and iron, with sulphide of manganese; (Mn, Fe) 2 

 (Mn 2 S)Be 3 (Si0 4 ) 3 . 

 Achtaragdite, a pseudomorph, perhaps after Helvite. 



367. Danalite; isometric; H—5.5-6; G=3.42; orthosilicate of iron, zinc, 



beryllium and manganese, with sulphide of zinc and iron; 

 (Fe, Zn, Mn) 2 ([Zn, Fe] 2 S)Be 3 (Si0 4 ) 3 . 



368. Eulytite; isometric; H=4.5; G=6.106; orthosilicate of bismuth; Bi 4 



(SiO,) 3 . 



369. Zunyite; isometric; H=7; G=2.875; a highly basic orthosilicate of 



aluminum; (Al[OH,F,Cl] 2 ) 6 Al 2 (Si0 4 ) 3 . 



4. GARNET GROUP. Isomeiric, Holohedral. 



370. Garnet; isometric; H=6.5-7.5; G=3.15-4.3; an orthosilicate of one or 



more of the bivalent elements calcium, magnesium, ferrous iron or 

 manganese, combined with one or more of the trivalent elements 

 aluminum, ferric iron, chromium, or titanium; general formula, 



R 3 R 2 (Si0 4 ) 3 . 



1. Aluminum Garnet. 



Sub-Species I. Grossularite; Calcium-Aluminum Garnet: 

 . Ca 3 Al 2 (SiO i ) 3 ; G=3.55-3.66. Var. (a) Wiluite is pale, gooseberry 

 green; (b) Essonite or Cinnamon- Stone is cinnamon brown to wine 

 yellow; Hyacinth belongs here; ( c ) Succinite is amber -colored ; (d) 

 Romanzovite is brown; (e) Rosolite or Rose Garnet is rose pink, from 

 Mexico. 



Sub-Species II. Pyrope; Magnesium-Aluminum Garnet; Mg 3 

 Al 2 (Si0 4 ) 3 ; G=3.70-3.75; color deep to dark red; when transpar- 

 ent it is called Precious Garnet. 



Sub-Species III. Almandite; Iron-Aluminum Garnet; Fe 3 

 Al 2 (Si0 4 ) 3 ; G=3. 9-4.2; color deep red to violet; when transparent 

 it is called Precious Garnet or Almandine Garnet; if cut en cabochon, 

 Carbuncle; when opaque and brownish-red it is called Common 

 Garnet. 



Sub-Species IV. Spessartite; Manganese-Aluminum Garnet; 

 Mn 3 Al 2 (SiO i ) 3 ; G=4.0-4.3; color dark hyacinth to brownish-red. 



2. Iron Garnet. 



Sub-Species V. Andradite; Calcium-Iron Garnet; Ca 3 Fe 2 

 (Si0 4 ) 3 ; G=3. 8-3.91. Var. (a) Simple Calcium-Iron Garnet; in- 

 cludes: 1, Topazolite, crystallized, lemon-yellow; Demantoid is in 

 pebbles, grass- to emerald-green, and highly-prized as a gem ; 2. 

 Colophonite is granular, brownish, resinous; 3. Melanite is crystal- 

 lized, black; Pyreneite is a grayish-black Melanite; 4. Jelletite is a 

 green or yellowish variety in small crystals (from Switzerland); 

 Calderite is massive (from India), one kind resembles Colophonite. 

 (b) Manganesian Calcium-Iron Garnet; includes: 1. Rothoffite and 

 Allochroite, massive and brown, yellowish or reddish-brown ; 

 PolyadelpMte is brownish -yellow from Franklin Furnace; Bredberg- 

 ite is from Sala; 2. Aplome is a dodecahedral, striated, brown to 

 yellowish-green varietv. (c) Titaniferous Garnet; graduates 

 towards Schorlomite, Ca 3 (Fe,Ti,Al) 2 ([Si,Ti]0 4 ) 3 ; color black, (d) 

 Yttriferous Calcium-Iron Garnet or Ytter ■garnet, contains yttria. 



3. Chromium Garnet. 



Sub-Species YI. Uvarovite; Calcium-Chromium Garnet; 

 Ca 3 Cr 2 (SiO + ) 3 ; H=7.5; G=3.41-3.52; color emerald-green, crys- 

 tallized. Trautwinite is an impure variety- 



371. Schorlomite; isometric; H=7-7. 5; G=3. 81-3.88; a titano-silicate of cal- 



cium, iron and titanium; Ca 3 (Fe,Ti) 2 ([Si,Ti]0 4 ) 3 . Ivaarite ig 

 probably identical, or a variety. 



