. Guide leaflet. CALCITE FROM SCHNEEBERG, SAXONY, GERMANYPlate-like (Irystals which are massed in rounded piles resembling sheet a of paper is THE COLLECT/OX OF MINERALS 19 among mineral species of the manifold expression of the law of symmetryin crystallization, which in this instance among thousands of complexmanifestations preserves a three-fold symmetry. The series of crystal-lized calcite in Cases 8 and 9 well illustrates the wide range of formscharacteristic of this mineral, from the simple rhombohedra from Porettaand the six-sided prisms from Saxony to the highly complex modifica-tions
. Guide leaflet. CALCITE FROM SCHNEEBERG, SAXONY, GERMANYPlate-like (Irystals which are massed in rounded piles resembling sheet a of paper is THE COLLECT/OX OF MINERALS 19 among mineral species of the manifold expression of the law of symmetryin crystallization, which in this instance among thousands of complexmanifestations preserves a three-fold symmetry. The series of crystal-lized calcite in Cases 8 and 9 well illustrates the wide range of formscharacteristic of this mineral, from the simple rhombohedra from Porettaand the six-sided prisms from Saxony to the highly complex modifica-tions from Cumberland and ARAGONITE FROM EISENERZ, STYRIAStalactites of calcium carbonate sometimes form branching forms resembling coral Dolomite, the carbonate of calcium and magnesium; siderite, thecarbonate of iron, and rhodochrosite, the carbonate of manganese, allbelong in the same group with calcite and have many of the char-acteristics of form which were seen in that mineral. They are bestdistinguished from calcite by the fact that they unite in curved group-ings and by their differences of color. The series of siderite ((ases 9) andrhodochrosite (Case 10) are especially fine. Aragonite is a second form ofcalcium carbonate and one which crystallizes in an entirely differentway from calcite. Among the suite in Case 10, attention is particularlydirected to the branching coral-like forms which distinguish the cave 20 AMERICAN MUSEUM CI IDE LEAFLET deposits of aragonite and which, with their delicate lacework of finestalactitic stems, constitute objects of great attractiveness of form. Cerussite, the carbo
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectnatural, bookyear1901
