Why Do
Spinels and Rubies Sometimes Form Together?
You may be wondering how
it is possible for spinels and rubies to be found together. Let's discuss about it in our
new article!
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3 min
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Science
Gem-related Field
Spinel
A Simple Coincidence?
You may be wondering how it is possible for
spinels and rubies to be found together. Well, it is not surprising as they both come from
the same metamorphic mineral (limestones, crystalline schists, gneisses, and serpentines).
They are also present as a predominant mineral in rare mafic igneous rocks. So let's try to
not be too complicated with details, and go straight to the point! Magmas in these igneous
rocks are very poor in alkalis compared to aluminium. However, aluminium oxide may develop
as a mineral corundum (to form rubies) or may be mixed with magnesia to form spinel.
Spinel petrogenesis in mafic magmatic rocks is still highly disputed but is
likely the result of mafic magma encounters with more advanced magma or rock.
Fun fact: Two thousand years ago, gem traders believed that each and every
bright red gem was a "ruby" and every soft blue gemstone was a "sapphire." As a result, many
spinels are still in very significant jewelry collections based on their erroneous
designation as ruby.
Details of this stone: Stone type: Spinel
Certified: No Color: Greyish-Blue
Origin: Sri Lanka Treatment: None
Shape & Cut: Cushion Weight (cts): 2.99 Dimensions (mm): 9x7.1x5.15 Single/pair:
Single
THE QUESTION
What Differentiates Spinels
From Rubies?
The ruby has a trigonal crystal structure,
which implies it fluoresces in candlelight or daylight, but large stones are rare these
days, while spinel has a cubic, sequentially refractive structure, comparable to a diamond,
which leaves the stone bright and vivid. Rubies are aluminium minerals with traces of
chromium that give them their red hue while spinels are magnesium aluminium minerals.
Spinels can also be found in other tones, such as black, violet, and the very rare cobalt
blue.
Jay Spinel
2.99 cts
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Benjamin Poudevigne
Social Media Manager at
BespokeGems
With over ten years of marketing
experience, I finally decided to settle down in Bangkok to work in an area that I have
always been interested in: the gemstones industry. I'm still learning how the market works
on a daily basis, and I enjoy sharing my experience with those who are interested in
learning more about gems in general.