Displaying 301 - 400 of 42079
Cat. # Name Description
301 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.
302 Copper Not found in catalog.
303 Pyrite Pyrite in black tourmaline.
304 Calcite With iron disseminated, decomposed marcasite present
305 Feldspar None
306 Carnallite None
307 Wolframite None
308 Pyrite Granular aggregates (ore). ! thumbnail with quartz.
309 Quartz, amethyst None
310 Quartz, geode Fragment.
311 Sphalerite Hand- nice black crystal cluster. Miniature - calcite cleavage fragment Color: BR
312 Quartz None
313 Quartz None
314 Feldspar Oligoclase.
315 Feldspar Oligoclase.
316 Calcite Calcite. Dysaralite.
317 Vesuvianite None
318 Pyrite Concretions, some decomposition similar to (CS 428 4).
319 Sphalerite Massive sphalerite cementing pieces of matrix. Color: BR
320 Quartz, geode Quartz geode lined with botryoidal chaldedony.
321 Calcite Grotesque argillo calcareous concretion.
322 Calcite Argillo-calcareous concretions.
323 Limonite One-half large concretion. Color: BR
324 Hematite Variety martite; shows octahedrons clearly. Color: BR
325 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."
326 Marcasite Nodule.
327 Pyrite Interesting cluster of darkened crystal cubes.
328 Quartz, geode Bitumen, bearing geode.
329 Quartz Quartz, geode. Peculiarly encrusted crystals.
330 Marcasite Nodule.
331 Barite Barite/sandstone rose.
332 Calcite Concretion about a root
333 Calcite Vein, in coal.
334 Calcite Vein filling.
335 Gypsum Concretion.
336 Bournonite Massive, metallic luster; dark gray with pyrite.
337 Hematite Botryoidal. Color: RD-BR
338 Marcasite Nodule.
339 Limonite Fibrous.
340 Copper Quartz.
341 Copper Native copper.
342 Copper Native copper.
343 Calcite [Cephenomenal boulderet.(original catalog description)] Calcite crystals with vitreous encrustation on dark massive limestone/dolomite. Color: ML
344 Pyrite Iron pyrites, fossil?
345 Quartz Illustrative materials.
346 Quartz Geodes.
347 Dolomite White dolomite crystals covering specimen.
348 Dolomite None
349 Dolomite None
350 Dolomite None
351 Barite Misidentified as dolomitic material.
352 Barite Misidentified as dolomitic material.
353 Wulfenite None
354 Scheelite Pale gray, massive.
355 Wulfenite Small, golden cubes in vugs.
356 Heulandite None
357 Nickeline Massive. Color: PK-OR
358 Diopside (Pyroxene group) Pyroxene, var. Diopside.
359 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.
360 Aragonite None
361 Aragonite Twinned crystals.
362 Realgar Massive on matrix, glassy coating. Color: RD
363 Garnet group Color: YL
364 Almandine (Garnet group) Crystals in nephelite - syenite matrix. Color: RD BR
365 Calcite Catalog says "Two cards present. One says: Drusy surface of carboniferous limestone, Mahaska Co., Iowa. The other says: dogtooth spar on iridescent surface of limestone."
366 Copper None
367 Sphalerite Massive sphalerite cementing pieces of matrix. Color: BR
368 Pyrite Similar to but listed in old notebook as "astrocarpus" ???
369 Columbite (Tantalite group) Massive. Color: BK
370 Enargite Dark gray, massive.
371 Autunite Yellow flat crystals scattered on matrix.
372 Calcite Geode.
373 Skutterudite Massive. Color: SL-YL
374 Skutterudite Massive; var. smaltite. Color: SL-YL
375 Nickeline Massive. Color: YL
376 Muscovite Microcrystalline. Color: YL
377 Siderite None
378 Barite Massive, pink.
379 Muscovite Muscovite mica.
380 Gypsum Curved crystal groups on matrix, selenite.
381 Pyrite Stalactite
382 Pyrite Stalactite
383 Pyrite Stalactite
384 Pyrite Stalactite
385 Pyrite Stalactite
386 Pyrite Stalactite
387 Pyrite Stalactite
388 Pyrite Stalactite
389 Pyrite Stalactite
390 Pyrite Stalactite
391 Pyrite Stalactite
392 Pyrite Stalactite
393 Chalcopyrite Crystals on dolomite crystal matrix.
394 Quartz Crystals.
395 Quartz Quartz, rock crystals.
396 Quartz Botryoidal. Inside of geode.
397 Quartz Iron, stained quartz crystals.
398 Quartz Geode.
399 Aragonite Twinned crystals.
400 Halite Massive.