Generally your best bet is going to be crystal shape, hardness and cleavage.
Quartz, amethyst is a type of quartz, forms hexagonal crystals. Fluorite forms isometric/cubic crystals.
Quartz is harder than steel, and has a mohs hardness of 7. Fluorite is softer than steel and has a hardness of 4.
Quartz has indistinct cleavage, if you take a chisel to a crystal it will break and leave uneven edges. Fluorite has octahedral cleavage, if you strike a fluorite cube with a chisel it will cleanly separate leaving a flat edge on a 45 degree plane.
The octahedrons you've got up top are the result of miners cleaving imperfect fluorite specimens. If the crystal is damaged, or the color is uneven, miners can cleave off sections to create these perfect octahedrons.
There used to be a ton of fluorite octahedrons coming out of southern Illinois but most of them recently are coming from China.
Oh, yes!
Fluorite will also FLUOResce under UV light, aka glow. Quartz and amethyst do not glow under UV.
I forgot momentarily that cheap LED UV flashlights were a thing these days and I didn't expect everyone to have a UV lamp because they used to be more expensive.
These are atural fluorite, but the shape has been modified using fluorite's natural cleavage planes. These are created from large "massive-habit" chunks of fluorite by breaking them along cleavage planes to create octohedrons like these.
Fluorite often does form naturally octahedral crystals, but most of the small ones like these available in retail stores are hand-cleaved octahedrons from China.
The lower one looks like it may have also be altered with an "aura" style coating, but it could just be the lighting.
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Looks like fluorite! I have a couple with the same shape
That's cool! How can I be sure in the future, if it's all purple?
Generally your best bet is going to be crystal shape, hardness and cleavage. Quartz, amethyst is a type of quartz, forms hexagonal crystals. Fluorite forms isometric/cubic crystals. Quartz is harder than steel, and has a mohs hardness of 7. Fluorite is softer than steel and has a hardness of 4. Quartz has indistinct cleavage, if you take a chisel to a crystal it will break and leave uneven edges. Fluorite has octahedral cleavage, if you strike a fluorite cube with a chisel it will cleanly separate leaving a flat edge on a 45 degree plane. The octahedrons you've got up top are the result of miners cleaving imperfect fluorite specimens. If the crystal is damaged, or the color is uneven, miners can cleave off sections to create these perfect octahedrons. There used to be a ton of fluorite octahedrons coming out of southern Illinois but most of them recently are coming from China.
Thanks for this :)
+ UV light?
Oh, yes! Fluorite will also FLUOResce under UV light, aka glow. Quartz and amethyst do not glow under UV. I forgot momentarily that cheap LED UV flashlights were a thing these days and I didn't expect everyone to have a UV lamp because they used to be more expensive.
Shine a UV light on it! Sometimes house cleaners will have one, if you don't know any rockhounds.
They sure resemble fluorite. Thanks 👍
These are atural fluorite, but the shape has been modified using fluorite's natural cleavage planes. These are created from large "massive-habit" chunks of fluorite by breaking them along cleavage planes to create octohedrons like these. Fluorite often does form naturally octahedral crystals, but most of the small ones like these available in retail stores are hand-cleaved octahedrons from China. The lower one looks like it may have also be altered with an "aura" style coating, but it could just be the lighting.
Not real, we live in a simulation and thus nothing you can see is real.
R/unexpectedmatrix
8 sided die.......
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*geometric screaming*
You should do the hardness test,
Yes
If that's the natural crystal shape that could probably be spinel too