396 DESCRIPTIVE MINERALOGY. 



LOCALITIES. 



Jefferson County. At the Sterling ore bed in the town of Antwerp, spathose iron is found 

 in rhombohedrons of a yellow and reddish brown colour, with crystallized quartz, specular 

 iron, and the rare cacoxenite. It is not abundant, and it probably passes into the ankerite 

 described further on. 



St. Lawrence County. At the Dodge ore bed in the town of Hermon, this mineral occurs 

 in the form of primary crystals, which are of a yellowish colour, and have their faces bent. 



Schoharie County. The septaria found in this county and elsewhere, usually have minute 

 crystals of a dark brown colour, with a semi-metallic lustre. They line the seams and cavi- 

 ties, and are usually associated with heavy spar. 



In Connecticut, there is a vein of spathic iron of considerable extent at Roxbury, where it 

 is associated with quartz in a mountain of gneiss. 



ANKERITE. 

 [In honor of Prof. Anker, of the Johannseum in Gratz.] 

 Ankerite. Phillips and IVuimson. — Paratomous Limestone. Jameson. — Paratomes Kalk-Haloid. Mohs 7 

 Fig. 473. 



Description. Colour white, sometimes tinged with yellow and 



\ brown. Streak white. It occurs in crystals or crystalline masses. 



\ The primary form is a rhombohedron. Fig. 473. P on P' 106° 12'. 



^^ Cleavage perfect, parallel with the primary faces. Fracture uneven. 



1 \ .--''' ^)\ 1 Lustre vitreous. Slightly translucent. Hardness from 3.5 to 4.0. 



U--'' \^^ r \ 1 Specific gravity from 2.95 to 3.10. Before the blowpipe alone, it 



\ 1 M becomes black and acts on the magnet, but does not melt ; with borax, 



\. I ^-^ it melts into a pearl. Soluble in nitric acid, with a brisk effervescence. 



Composition. Carbonic acid with oxide of iron 35.31, lime 50.11, magnesia 11 .85, oxide 

 of manganese 3.08 (Schrotter). Carbonate of lime 51.10, carbonate of magnesia 25.70, 

 carbonate of iron 2 . 00, carbonate of manganese 3 . 00 (Berthier). 



Geological Situation. This mineral was first found in the Stjnrian mines. 



localities. 



Warren County. There is still some uncertainty in regard to this mineral. It seems to 

 be intermediate in composition between brown spar and the true spathose iron, the transition 

 being oftentimes almost imperceptible. I received a specimen from Dr. Emmons, the locality 

 of which is Johnsburgh in the above county, which more nearly approaches this species than 

 any other. This mineral has a dark brown colour, and a somewhat metallic lustre. Specific 

 gravity 2.88. Hardness about 3.5. The angle of the rhombohedron is about 106°, but the 



