A fun little geology primer...

Discussion in 'Growing Organic Marijuana' started by FunTimeGrowHap, Mar 12, 2012.

  1. #1 FunTimeGrowHap, Mar 12, 2012
    Last edited by a moderator: Mar 12, 2012
    Alright friends, a couple of people asked me to ID some rocks for them, but I'm not really comfortable making guesses from what I get as far as online descriptions go, so I'm hoping to arm you with the ability to figure it out for yourselves. Hope this helps someone.

    First up, igneous rocks. These are rocks that are made from lava or magma. They are grouped into two basic types of texture and three types of composition for classification purposes. All of these rocks can be identified by sight alone.

    The texture of the rock is decided by how it cools. If a volcano spews out lava, it cools very quickly and makes a rock that appears to be of a uniform color, like the rope-y looking black rock being formed daily in Hawaii (basalt). If magma cools down at a much slower pace under the surface of the earth, the different minerals that make up the magma have time to form crystals, resulting in rocks like granite. Let's just call the the fast coolers extrusive and the quick coolers intrusive for now.

    We can gather a fairly accurate idea of the rocks mineral composition by color alone. Black igneous rocks are referred to as mafic. A typical sample would be primarily made of pyroxine with some amphibole and plagioclase, maybe even a little olivine. Mostly white igneous rocks are called felsic and contain a higher level of plagioclase along with minerals like quartz and orthoclase. Rocks that are in the grey area between the two extremes are referred to as intermediate. That's smart.

    Now get ready for the fun part....I've got a table that lets you identify igneous rocks and deduce their mineral content with just a quick glance. Hold on to your butts.

    Redirect Notice

    Next time, we get started with some mineral identification. BWAHAHAHA!:devious:
  2. w00t! First in! :D

    pulls up a bean bag chair, starts taking notes and rolling a fat J
  3. #3 hope2toke, Mar 13, 2012
    Last edited by a moderator: Mar 14, 2012
    nice, mr. Fun time. thanks for posting, i will need to re read that because it went over my head, can i ask if its possible for you to paste the image into the Gc. next rock type so i can view the table in window... great topic...

    edit- i would post them but i cant even access the chart syou linked to. Additionally I am an Etart as well, so that makes it twice as difficult. even more difficult because i am a visual learner

  4. #4 FunTimeGrowHap, Mar 13, 2012
    Last edited by a moderator: Mar 13, 2012
    Could you be a dear and do it instead? I'm a bit of an e-tard.

    Here's a place to get started with mineral identification: http://library.thinkquest.org/J002289/ident.html

    Familiarize yourselves with luster, cleavage, the moh's hardness scale, streak, blah, blah, and blah,. There are a couple of other fun tests (hydrochloric acid, tasting), but I don't think we'll be needing them. With the basic tests down, you should be well on your way. I'll post descriptions of how some of the more common minerals respond to our testing gamut later.

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