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4meter

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4meter last won the day on January 26 2016

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About 4meter

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    Male
  • Location
    Tucson, Arizona
  • Interests
    rock/mineral/fossil collecting; geology; meteorology; astronomy; sailing; good food; wood working; afternoon naps.

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  1. Its not fossil corals but Quartz Boxwork or Cellular Limonite; in this case, the soluble materiel has chemical weathered away leaving only the quartz. Boxwork is associated with mineral deposits but also forms in limestone and as cave deposits. You have found some nice samples!
  2. That is one beautiful stone! I'm sure this is a fault breccia (rocks broken into small fragments by a moving crack in the ground (fault), then fragments were re-cemented together (the gray lines through the rocks). Later erosion broke a part off of the large rock mass and water rounded the broken piece into the beauty that you collected. Thanks for sharing with us!
  3. Based on the close up photos: Sample 1 is a Gneiss; Samples 2, 3 & 4 are Sedimentary rocks. # 2 & 3 are an iron rich mudstones and # 4 is a silty shale. Nice samples to add to your rock collection. Thanks for sharing with us.
  4. You have a beautiful piece of concrete. Really, man made concrete. It will fizz like mad if you put acid or warm vinegar on it.
  5. Not a meteorite and not Basalt, basalts are not magnetic. It is wast slag with some iron in it.
  6. I'm with Haderly on this one. It's a Lapillistone, a volcanic rock made up of rounded, pebble sized, lava blobs called lapilli. It does look like any Stromatolites I have observed. Lapillistones can be very pretty once cut and polished. Nice find!
  7. A few of the larger, solitary, crystals look to have flattish tops. Calcite (boxwork) as d-day said.
  8. Oooo, a sample from my neck of the woods. d-day has it right. It's a conglomerate with an iron cementing material. The sample was, very likely, in the bottom a pot hole of a cascade or fall and was hollowed out by the action of water. It's most likely Pennsylvanian in age. In the good old days, kids of the region would collect agates, break them into rough squares, and place these into pot holes of the areas streams, during the late spring & summer. The action of the water during these low flow periods, would round the agate pieces, and the kids would collect their newly made marbles at the end of Summer. Most were plain but a few tumbled into spectacular marbles.
  9. I would leave open the very, very unlikely possibility that the sample is topaz, but... I blew up your photos of the scratch test. It clearly shows the sample gouged out and "white" dust along the gouges. It also shows a metallic streak on the sample. Your diamond blade has a small amount of tiny, industrial grade, diamonds embedded in lots of alloy. The diamonds, gouged out spots in the sample and left the gouge and white dust, the alloy, being softer than your sample, smeared on the sample leaving the metallic streaks. I stick with quartz or feldspar. Nothing seen so far to point to an exotic like topaz or other hard minerals. I stopping trying to use blades or mineral fragments to do hardness tests; the results were never easy to see. Get a Moh's hardness test kit (metal tipped points that are calibrated) for tile testing from Amazon (when in stock) or a tile supply store; they are worth every penny if you do a lot of rock/mineral hunting.
  10. Its not a diamond or corundum. Your blade did scratch it. It is just a piece of weathered quartz, maybe weathered feldspar.
  11. It would be a Breccia if it was a true rock, but in this case it is bits of stone mixed in concrete thus, concrete aggregate.
  12. Congratulations! you discovered concrete aggregate. Had a sample similar to this on a Petrology final that we were suppose to I.D.. It really bamboozled all of us taking the test. During the after test briefing, it was revealed the sample was just concrete from a demolition site on campus. Boy, did we feel silly.
  13. Great find for a pile of dirt! There sure is a lot of nice minerals up there in the Vulture Mine area. One day I hope to get up there and do some digging myself.
  14. Very Nice collection of crystals Mike! Best guess based solely on the photos: Mostly Beryl, some Apatite, Topaz (?), iron stained Quartz and a piece of Hornblende with some other mineral on it (see attached, annotated photo).
  15. Your PDFs are just the cleavage striations on the plagioclase feldspar fragment within the sample and the needle shaped minerals could be any number of minerals which develop under various metamorphic temperature/pressure conditions. Again, all evidence shows your sample to be a fractured, metamorphic rock. To see "shocked quartz" features that a diagnostic of a meteorite strike; that is the slight deformation of the country rock and tale, tale shearing (shocking) of the quartz grains within the host rock, you need more than 60X; you need an electron-microscope. One usually looks for "cone in cone" type mega-features in the host rock, during field work that is supported by evidence shock quartz seen under lab conditions to identify a meteorite strike. The bottom picture looks like a view in polarized light with cross analyzers. How did you get that picture?
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