 | | Report (issue) | | the cover—Turquois crystals from Lynch Station, Virginia; x ca.; pho tograph by Neal Ycdlin; color plates...C. A. Michael. COLD NUGGET FROM SPOTSYLVANIA COUNTY: Longest dimension approximately 13 cm., photograph...of Virginia R. V. DIETRICH* Professor of Geology and Associate Dean of Arts & Sciences, Virginia Polytechnic...Polytechnic Institute Research Division Bulletin 47 Virginia Polytechnic Institute, Blacksburg, Va. 24061 *... © R. V. Dietrich and the Research Division of Virginia Polytechnic Institute, 1970 Printed and bound |  | | Book | | ---------_ Sylvite -----------------------· __ Fluorite Cryolite Carbon~tes Calcite ________________________...cleavage in three directions, at right angles, cubic. FLUORITE-perfect cleavage in four directions, at more than...(Selenite) 7-Quattz (Rock Crystal) 3-Calcite 8-Topaz 4-Fluorite 9-Corundum 5-Apatite 10--Diamond The hardness...Survey) Chester County, Pa.: Alabama; Texas; Montana: Humbolt County, Nevada; Beaver County, Utah; Loudon...Loudon ~unty, Virginia; Wake County, North Carolina; Albany County, Wyommg; and Kern County, California. Natural |  | | Book (edition) | | h = (a Frequently observed on galena (PbS) and fluorite (CaF 2 ). , , . <*> : : : ; : FIG. 78...= (a coa coa), {100} e served on copper (Cu), fluorite (CaF 2 ), and halite (NaCl). Figure 84, h = (a...clearly that six, and through Fig. 101 only three. fluorite class, has the symmetry of the hexoctahedral...is Fig. 286. spinel. A penetration twin of fluorite Here, two cubes interpenetrate according to the...Feldspar, 2. Gypsum, 7. Quartz, 3. Calcite, 4. Fluorite, 5. 8. Topaz, 9. Corundum, Diamond. 10. |  | | Book (edition) | | {110}. Frei quently observed on galena (PbS) and fluorite (CaF»). Figure 79,d = (a: a: «a), {110}; 7 = (a:...Figure 83, h = (a: a: a), Observed on copper (Cu), fluorite (CaF2), and halite (NaCl). Fig. 80. Figure ...and 99 show three cubes representing crystals of fluorite (CaF 2) (Fig. 97), sphalerite (ZnS) (Fig. 98)...clearly that six, and through Fig. 99 only three. fluorite has the symmetry of the hexoctahedral class, sphalerite...crystal of the mineral spinel. A penetration twin of fluorite is shown in Fig. 283. Here, two cubes have intergrown |
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