MINERALOGY. 455 



resinous; streak brown. H. = 5.5. G. = 4.3 to 4.5. 

 Found in serpentine rocks of Silesia, Styria; in the 

 United States, Maryland. New York, Pennsylvania, 

 Connecticut. The compounds of chrome are extensively 

 used as pigments. Chromate of lead is the chrome yellow 

 of the painter ; used also in calico printing, dyeing, and 

 painting of porcelain. The green oxyd of chromium 

 gives its own color to glass, enamel, and is also employed 

 in coloring porcelain, and chromic acid is said to be the 

 red coloring matter of the red sapphire or ruby. 



Red Iron OrePeroxyd of Iron. Partly crystal- 

 like ; often massive, granular ; color dark, steel-gray, or 

 iron-black, sometimes of variegated shades ; streak pow- 

 der, cherry-red or reddish-brown. But slightly attracted 

 by the magnet. H. = 5.5. G. = 5.0 to 5.3. Occurs 

 in the primitive and sedimentary rock formations, in 

 Switzerland, region of the Rhine, mountains of Black 

 Forest. Very abundant in the United States. Pilot 

 Knob, in Missouri, is seven hundred feet high ; another 

 mountain, in the same region, is one hundred and fifty 

 feet high ; both consist mainly of this ore, piled, as it is 

 stated, in masses of all sizes, from a pigeon's egg to a 

 middle-sized church. Red Clay Ironstone, or Bloodstone, 

 is of a variety of more solid structure; earthy; conspic- 

 uous from its blood-red hue, passing into steel-gray. Found 

 in all the mountain metallic regions of Germany, and in the 

 Alps, mostly associated with the more earth-like, brownish- 

 red substance known as Red ochcr. Is an excellent iron 

 ore, but on account of frequent admixture with sulphur, 

 does not rank quite so high as magnetic iron. 



Brown Iron Stone Limonite Brown Hematite. 

 Usually massive, sometimes of lenticular form, and often 

 with a smooth, stalactitic surface, having a compact, 



