Displaying 301 - 400 of 40190
Cat. # Name Description
301 Calcite Modified rhombic crystals.
302 Millerite Sprays of crystals in large calcite crystals.
303 Calcite Geode with pyrite crystals with 2 particles of bitumen.
304 Calcite Pocket within calcareous tufa.
305 Calcite From a seam of coal; Iron pyrite stain on one side.
306 Calcite Crystal aggregate.
307 Calcite Fragment of calcite geode lined with rhomboidal crystals of calcite.
308 Calcite Cleavages.
309 Calcite Limestone bearing calcite crystals.
310 Calcite Carboniferous; Calcite crystals.
311 Calcite Satin spar.
312 Calcite Satin spar.
313 Calcite None
314 Talc None
315 Gypsum Translucent, blocky crystal group.
316 Marble Smoky
317 Barite Pinkish blades on dark calcite matrix with clear calcites.
318 Calcite Crystals.
319 Calcite Crystals.
320 Marcasite None
321 Galena Galena with quartz crystals.
322 Columbite (Tantalite group) This number has not been assigned a location in the catalog (number not found in catalog).
323 Goethite Color: BK
324 Goethite Dull, stalactitic. Color: BK
325 Quartz Granitoid quartz and mica.
326 Marcasite Marcasite & calcite crystals in small vug.
327 Calcite Very large and heavy; crystalline.
328 Quartz Quartz porphyry, var. Microgranite.
329 Talc Talc schist.
330 Hematite Crystals, 1/2" - 1/4", on matrix (after magnetite). Color: BK
331 Carnotite Yellow coating.
332 Perthite (Feldspar group) Pethite, a microcline - albite - perthite. Also monoclinic.
333 Chrysocolla Massive. Color: GR
334 Stannite Small, dark gray crystals.
335 Stannite Massive dark gray rock (broken in half).
336 Calcite Fragment of geode. This number not found in the catalog.
337 Heubnerite Crystals in quartz.
338 Jamesonite Gray, fibrous; other piece - shiny, brown (looks like road tar)
339 Melanterite Melanterite is one of only a few water soluble sulfate minerals. It forms in the near-surface secondary oxidation zone of ore deposits usually late in their development. In many mines, melanterite is an ongoing precipitate or efflorescent forming white to green encrustations, crystal aggregates and stalactites right on the sides of the mine's shafts. The primary source of the iron for melanterite is iron sulfides such as pyrite, pyrrhotite, marcasite and chalcopyrite. A technique for removing copper from the copper sulfate mineral chalcanthite is responsible for the naming of an alternate name for melanterite. Chalcanthite, like melanterite, is soluble in water and it thus makes a solution of copper sulfate. If metallic iron is added to the solution, then metallic copper precipitates, leaving a solution of iron sulfate. This left-over solution has the same composition as a solution made from dissolving melanterite. The alternate name for melanterite is "copperas", from the Greek meaning "copper water", an allusion to the left-over solution. In a way, this could be thought of as "copper-providing water". Attractive crystals of melanterite with a beautiful blue-green color are know to exist and are sought after. The shades toward blue come from impurities of copper which can substitute for as much as one third of the iron. The more copper, the bluer the crystals. Generally melanterite is known as having a white or green color. Melanterite is also the name of a group of only five monoclinic sulfates of which melanterite is the only somewhat common member. Members of this group have the same basic structure as melanterite, but can have in place of iron, ions of manganese, zinc, cobalt and copper. These are the members of the Melanterite Group: Bieberite (Hydrated Cobalt Sulfate), Boothite (Hydrated Copper Sulfate), Mallardite (Hydrated Manganese Sulfate), Melanterite (Hydrated Iron Sulfate), Zinc-melanterite (Hydrated Zinc Copper Iron Sulfate) PHYSICAL CHARACTERISTICS: Color is white, green, yellowish green or blue-green. Luster is vitreous to silky. Transparency: Crystals are translucent to slightly transparent. Crystal Habits include stubby prismatic or blocky to tabular crystals, sometimes as pseudo-octahedrons. Also acicular, fibrous and capillary and found as encrusting, stalactitic and concretionary masses. Cleavage is perfect in one direct but only distinct in another. Fracture is conchoidal. Hardness is 2 Specific Gravity is approximately 1.9 (well below average). Streak is white. Other Characteristics: Is soluble in water and may deteriorate with absorption of water. The taste has a sweet, astringent and metallic character. Associated Minerals are epsomite, chalcanthite, gypsum, pyrite, pyrrhotite, marcasite and chalcopyrite. Notable Occurrences include Minas de Rio Tinto, Spain; Rammelsberg, Harz Mountains, Germany and Falun, Sweden; and in the United States at Ducktown, Tennessee; South Dakota; Colorado; Bigham Canyon, Utah; Comstock Lode, Lincoln County, Nevada; Butte, Montana; at several mines in Arizona and at The Geysers in Sonoma County and at Leona Heights, Alameda County, California. Best Field Indicators are crystal habit, low density, associations, solubility in water, taste and color.
340 Copper Not found in catalog.
341 Pyrite Pyrite in black tourmaline.
342 Calcite With iron disseminated, decomposed marcasite present
343 Feldspar None
344 Carnallite None
345 Wolframite None
346 Pyrite Granular aggregates (ore). ! thumbnail with quartz.
347 Quartz, amethyst None
348 Quartz, geode Fragment.
349 Sphalerite Hand- nice black crystal cluster. Miniature - calcite cleavage fragment Color: BR
350 Quartz None
351 Quartz None
352 Feldspar Oligoclase.
353 Feldspar Oligoclase.
354 Calcite Calcite. Dysaralite.
355 Vesuvianite None
356 Pyrite Concretions, some decomposition similar to (CS 428 4).
357 Sphalerite Massive sphalerite cementing pieces of matrix. Color: BR
358 Quartz, geode Quartz geode lined with botryoidal chaldedony.
359 Calcite Grotesque argillo calcareous concretion.
360 Calcite Argillo-calcareous concretions.
361 Limonite One-half large concretion. Color: BR
362 Hematite Variety martite; shows octahedrons clearly. Color: BR
363 Calcite Concretions; "From a layer just above ferrous sand running into blue Kansanan Clay, and west up into Iowa ten or more feet above it. Now a line of gravel which I had considered B. G. After a while this calcareous matter moves out and underated layers of for. sand takes its place."
364 Marcasite Nodule.
365 Pyrite Interesting cluster of darkened crystal cubes.
366 Quartz, geode Bitumen, bearing geode.
367 Quartz Quartz, geode. Peculiarly encrusted crystals.
368 Marcasite Nodule.
369 Barite Barite/sandstone rose.
370 Calcite Concretion about a root
371 Calcite Vein, in coal.
372 Calcite Vein filling.
373 Gypsum Concretion.
374 Bournonite Massive, metallic luster; dark gray with pyrite.
375 Hematite Botryoidal. Color: RD-BR
376 Marcasite Nodule.
377 Limonite Fibrous.
378 Copper Quartz.
379 Copper Native copper.
380 Copper Native copper.
381 Calcite [Cephenomenal boulderet.(original catalog description)] Calcite crystals with vitreous encrustation on dark massive limestone/dolomite. Color: ML
382 Pyrite Iron pyrites, fossil?
383 Quartz Illustrative materials.
384 Quartz Geodes.
385 Dolomite White dolomite crystals covering specimen.
386 Dolomite None
387 Dolomite None
388 Dolomite None
389 Barite Misidentified as dolomitic material.
390 Barite Misidentified as dolomitic material.
391 Wulfenite None
392 Scheelite Pale gray, massive.
393 Wulfenite Small, golden cubes in vugs.
394 Heulandite None
395 Nickeline Massive. Color: PK-OR
396 Diopside (Pyroxene group) Pyroxene, var. Diopside.
397 Aragonite 277 Aragonite CaCO3, Cianciana, Sicily, Foote, Philad'a. Label says dana 814 Scheelite, Tetragonal, Ca WO4, Zinnwald, bohemia. Card says Dana 814, Ward, Tetragonal, scheelite, Ca WO$, Zumwald, Bohemia see 331-13.
398 Aragonite None
399 Aragonite Twinned crystals.
400 Realgar Massive on matrix, glassy coating. Color: RD