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Mineral ID?

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moonflower

moonflower

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!

minerals005.jpg

minerals004.jpg

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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:

Calcite.jpg


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
 
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
 
Drosera36 said:
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
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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
 
Oooooo...did someone say ROCKS?? :D 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.
 
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 :)
 
Oh those a pretty! I have been to that swapmeet thing in Quartsite AZ (I used to live about 30 mins away in a small hell hole called Blythe CA.) They have a huge rock a gem show every year it is realy neat and they sell all sorts of cool crap.
 
in a bit ill post a pic that will send PAK into a fit
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It doesn't take much to send me into a fit. LOL

I have been to that swapmeet thing in Quartsite AZ
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You've gone to QUARTZITE?!! Lucky you!! Geez, that's rock/mineral/fossil heaven!

I like fossils too and have a few. One of my favorites being the fossil ferns from St. Claire PA and also the lovely amber JBL gave me. :)

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
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If they have any FLUORITE for sale and will ship, let me know! :D Why can't I ever find anyone dissolving a collection, dang it?!

Of course...I have waaaaaaaay too many rocks.

Since there are some rock heads here, I might list some specimens in the NASC auction...like a piece of the windowpane wulfenite. They are good specimens especially since they are old ones.

I'll have to try to post some pics. I have some specimens that would blow you away they are so beautiful. Its hard to get a photo that will do them justice though.
 
BTW Rattler...have you ever checked to see if any of those sapphires asterate (star)?

That cabachon-looking one in the bottom of your photo almost looks like it would.

Might be hard to test something that small, but if you want to see if a piece of rough will asterate, put a small drop of either THICK clear oil or light Karo syrup. (You need something that is thick and clear so the drop will be rounded). Shine a flashlight on the drop of liquid and move it around. You'll see a star in the liquid if the specimen has that property to it.
 
lol PAK your going to have to check.............that photo is the sapphires i put up for auction last year.....you've got them :grin: the photo of all the rough on the other thread is my wife and my current collection of rough...........
 
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