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Is this Spinel?


#1

Can anyone indentify if the following is a spinel?


#2

I don’t think so - The rough does not look quite right to me. It appears to be a quartz ie Amethyst, though some of those do appear to have the spinel crystal top. Some Garnet also can be quite light mauve in colour. The picture isn’t enough to be able to give you a definite answer - Sorry Gemsforkp :slight_smile: however, their might be someone on this forum who might be able to give you a better answer especially if they are a mineralogist.
Regards Trev


#3

Thank you for your response. One thing I noticed is when I use the Neodymium magnet it repels will that confirms that this is Amethyst?


#4

If Neodymium magnet attract them, I think it’s garnet. :slight_smile:


#5

That is most odd. It does confirm it has iron in its matrix which suggest it is Garnet.


#6

I does not attract, it repels them.


#7

Sort of doesn’t make sense. It shows that it is magnetic due to iron or hematite which can be magnetic, however I would not be sure that this is a garnet. The minerals may be magnetic, however it should also be attracted one and repel the other. Have you tried both N & S poles of the magnet to see if repels bothways.
Trev:confused:


#8

Does Neodymium repel Amethyst? If so, these stones may be Amethyst. but what are the other verities of gems which show magnetic repulsion?


#9

No gemera - It does not. Amethyst is quartz and certainly is not magnetic.
I hope someone out there can give you a clue to what it could be. It really does not make sense!
Sorry - Trev


#10

u can identify by using refractometer and specific gravity, also thermal conductivity can help u to seperate spinel from garnet


#11

Resembles that of Almandine Garnet to me.


#12

There are tests that my ‘help’ to confirm what ur stones are, im posting a pic of a pendent that shows a great clue as to what these stones are, good test is RI, checking internals for specific inclusions for that material. The pend is always labeled as a garnet but the inclusions discount those guesses. Any guess from the forum as to what these are? Will post answer later-steve…


#13

try using UV torch if its shows fluorescence and single RI it will probably be spinel


#14

living in new York, I often collect garnet of small size. Just by looking I would say you have an almandine- pyrope. There is no sure fire way to tell just by looking, but they do look similar to the hundreds of small stones I have collected between my home in western ny and north Carolina.


#15

Seems Rhodolite garnet from India.


#16

I have several over 100 carat natural spinels. They all show cubic crystal habit, octahedrons, and trigons. I believe that you have garnet rough in your photos.


#17

We tested with a gem tester (not sure how accurate this is) it is infact Spinel. How and where can I get them certified?

I have 10 stones each weighing more than 12cts approx and 4 stones more than 16cts.
If this is certified spinel what would be the value and how can I sell them.


#18

How about some photos?


#19

Gem testers using a thermal response ie Presidum and cannot distinguish between synthetic ie man made Spinel and natural ie mined from the earth spinels.
Man made Spinel like man made Corundum is very common.
Man made and natural are the same identical chemical composition so most tests can’t tell you. Its usually only a magnified view to look for either synthetic Spinel inclusions ie curved striae and gas bubbles vs natural inclusions found in Spinel like needles or crystals that you can distinguish between the two.


#20

Here are some of the photos: