A popular guide to minerals : with chapters on the Bement Collection of minerals in the American Museum of Natural History, and the development of mineralogy . alena, bismuthinite, cinnabar, ar-gentite, mispickel, enargite, tennantite, meneghinite, jamesonite,bournonite, freieslebenite, proustite, pyrargyrite, stephanite, poly-basite, altaite, tetradymite, coloradoite, almost all the tellurides,cerargyrite, embolite, iodyrite, fluorite, uraninite, magnetite, hema-tite, ilmenite, cassiterite, calcite, dolomiite, siderite, barite, gypsum,apatite, wulfenite, vanadinite, crocoite, scheelite, wolfr
A popular guide to minerals : with chapters on the Bement Collection of minerals in the American Museum of Natural History, and the development of mineralogy . alena, bismuthinite, cinnabar, ar-gentite, mispickel, enargite, tennantite, meneghinite, jamesonite,bournonite, freieslebenite, proustite, pyrargyrite, stephanite, poly-basite, altaite, tetradymite, coloradoite, almost all the tellurides,cerargyrite, embolite, iodyrite, fluorite, uraninite, magnetite, hema-tite, ilmenite, cassiterite, calcite, dolomiite, siderite, barite, gypsum,apatite, wulfenite, vanadinite, crocoite, scheelite, wolframite, stol-zite, polycrasite, diamond (a diamond from Kimberley enclosed twograins of gold), sulphur, arsenic, antimony, tellurium, of gold have been considered as accretions made up ofsuccessive layers of deposit, although they show when polished andetched crystalline structure. Silver, like gold, crystallizes in the isometric system, but isusually found in threads, wires, or elongated crystals, these lattergroups forming branching arms or arrow-pointed blades, producedby crystals sprouting in directions parallel to the diagonals of an. <4-l o c w rt 3 H ^H t-t p, U -X ^ c3 c C3 W <u PQ ^ O u w GUIDE TO COLLECTIONS 111 octahedral face, while in massive condition it is found in plates,scales and nodules. Some attractive specimens are to be seen incollections illustrating these conditions, and in many mineral cab-inets the riietal is seen in limestone penetrating the rock in twistedand curved filaments, together with arborescent and encrustingforms. Some of the most beautiful silver specimens are found in asso-ciation with the native copper of Lake Superior, where it occursin grains, plates and crystals, having been deposited in conjunc-tion with the copper matrix in which it is now embedded. Mexicoand Peru have produced the most silver, and in Peru especiallynative silver abounds. In Peru a silver mass has been found whichweighed over eight hundred pounds
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectmineral, bookyear1912
