User Tag List

Informational! Informational!:  0
Likes Likes:  0
Page 1 of 3 123 LastLast
Results 1 to 8 of 20

Thread: Mineral ID?

  1. #1
    moonflower's Avatar
    Join Date
    Jun 2004
    Location
    New York
    Posts
    316
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Mineral ID?

    any rock hounds out there?

    i've always had a passing interest in minerals & fossils, and my mom had picked up these three specimens from a moving sale a few months back (i just got home to see them). i know the first one is garnet, i think the second is fluorite, and i have no idea what the third is (also fluorite?) it's got a very regular slanting pattern of breakage... what's the name? rhombus? it's a slanted rectangle, basically. and id's would be cool thanks!



    "Seeds? Oh yeah... sometimes I forget they grow from those. I feel like they should hatch or something."

    ~a friend's observation of my CP's

  2. #2
    白人看不懂 Drosera36's Avatar
    Join Date
    Aug 2004
    Location
    z5/6, Rochester, NY
    Posts
    2,017
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    For some reason I think halite with the last, but then again I'm no mineral expert. Lick it.

    -Ben
    He who can, does. He who can't, teaches. -George Bernard Shaw
    I love these shirts!!!
    My Growlist
    My Webpage

  3. #3

    Join Date
    Jun 2006
    Location
    Central PA
    Posts
    88
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    green flourite i think

  4. #4
    rattler's Avatar
    Join Date
    Oct 2003
    Location
    missing, presumed dead
    Posts
    8,554
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    prolly calcite, least it looks like it to me

    if its halfway clear put it over some newsprit or something and see if it does double refraction like this:



    if it does its calcite, if not its prolly fluorite or halite, of these two rince it off with water and touch your tongue to it, if its salty its halite if not prolly fluorite
    cervid serial killer
    Know guns, know peace, know safety. No guns, no peace, no safety
    I didn't get stimulated but he kept his promise on change, that's about all I got left!
    http://www.wolfpointherald.com/--http://www.safety-brite.net/

  5. #5
    白人看不懂 Drosera36's Avatar
    Join Date
    Aug 2004
    Location
    z5/6, Rochester, NY
    Posts
    2,017
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    rattler, calcite has cleavage not at 90 degrees, which causes the double images. But, this mineral she has looks to be 90 degrees, so it's not going to be calcite. Also, a dilute bit of HCL will make it fizz if it's calcite.

    Errg wait never mind, I re-read it and she says it's a rhombus shape.

    -Ben
    He who can, does. He who can't, teaches. -George Bernard Shaw
    I love these shirts!!!
    My Growlist
    My Webpage

  6. #6
    rattler's Avatar
    Join Date
    Oct 2003
    Location
    missing, presumed dead
    Posts
    8,554
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Drosera36 View Post
    rattler, calcite has cleavage not at 90 degrees, which causes the double images. But, this mineral she has looks to be 90 degrees, so it's not going to be calcite. Also, a dilute bit of HCL will make it fizz if it's calcite.

    Errg wait never mind, I re-read it and she says it's a rhombus shape.

    -Ben

    Ben.......rhombus, 90 degrees.......can be hard to tell from a single photo plus ive had my hands on calcite specimens that LOOKED like they had 90 degree cleavage but fizzled and did the double refraction as well as having my hands on halite specimens that looked rhombus.......colored calcite specimens are VERY common and the specimen he has looks to be clear enough to check the refraction which is why i suggested he start there.........was just suggestions and i am not willing to bet money on it unless i have the specimen in hand
    cervid serial killer
    Know guns, know peace, know safety. No guns, no peace, no safety
    I didn't get stimulated but he kept his promise on change, that's about all I got left!
    http://www.wolfpointherald.com/--http://www.safety-brite.net/

  7. #7
    Moderator Schmoderator Fluorescent fluorite, England PlantAKiss's Avatar
    Join Date
    Aug 2001
    Location
    Richmond, Virginia/Zone 7
    Posts
    10,335
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Oooooo...did someone say ROCKS?? Man, what a great find for a moving sale. I just spent almost $200 on specimens at a yard sale. Of course the yard sale was put on by 3 rockhound/dealers. hehe I bought a flat of fantastic windowpane wulfenite collected back in the 50s.

    First specimen is garnet...looks like in mica schist although hard to tell from the photo. But garnet is often found in mica schist.

    Second specimen looks like massive fluorite. Fluorite is my favorite mineral but I prefer crystalized specimens. I have 70-80 fluorite specimens. I'm an addict. :-/

    Third one doesn't look like a rhomb (rhombohedron) to me... it looks cubic. My first thought is green calcite. Calcite is found in many colors. Often it does occur as rhombs like Rattler's optical calcite. However not all calcite refracts like that so that's not a reliable test. Calcite is found in many crystal forms. It could be fluorite although the cleavage doesn't look like it. Try sticking it under a black light and see if it fluoresces. Both calcite and fluorite can fluoresce but I've never seen green calcite fluoresce. And not all green fluorite fluoresces. I think I'd go with calcite.

    For excellent mineral info and photos, check out www.mindat.org.

    Rattler...have you ever seen ulexite? That will bring an image up to the top of the specimen when its cut flat and polished. Its really cool stuff.

    Nice specimens. One of these days I'll have to post some mineral photos.
    "Fox terriers are born with about four times as much original sin in them as other dogs." - Jerome K. Jerome

  8. #8
    moonflower's Avatar
    Join Date
    Jun 2004
    Location
    New York
    Posts
    316
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    thanks, PAK! i should have guessed from your avatar that you were into rocks!!! the angle of the picture does make it look like a cube now that i look at it... it's decidedly slanted in person though since you mentioned calcite, i had a "duh" moment and compared it to my specimen of Iceland spar, and lo and behold they seem to have the same cleavage pattern. looking good to be green calcite then? i'll try to hunt down a UV light to test it for fluorescence... that could be fun

    lol actually the couple who sold my mom these three specimens had HUNDREDS of others, they only moved a few miles away and were interested in selling even more of them... i'm more of a fossil person than rock/mineral person (but still learning both... earth science is actually the only natural science i haven't been forced to take in college!) but it's all cool
    "Seeds? Oh yeah... sometimes I forget they grow from those. I feel like they should hatch or something."

    ~a friend's observation of my CP's

Page 1 of 3 123 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •