Yes, the term synthetic doesn't define the material, only its origin. In a mineralogical case it should be used as an adjective. It needs a noun to be used with any precision.
Joined: Tue Apr 05, 2016 7:58 pm Posts: 1424 Location: San Marcos, CA
Yes, I guess I was making a further point, in the trade many things are sold under the synthetic umbrella. But as you stated many are imitations and simulants.
It would seem that this poll ended before it began. Would synthetic opal be a mineral?
I agree with Barbara. Natural Opal, being amorphous is probably not properly called a mineral but maybe a mineraloid.
"the difference between mineral and mineraloid is that mineral is (geology) any naturally occurring inorganic material that has a (more or less) definite chemical composition and characteristic physical properties while mineraloid is a substance that resembles a mineral but does not exhibit crystallinity."
To settle the original question. The Merriam-Webster dictionary actually has an entry for synthetics as being minerals.
Mineral:
"b: a synthetic substance having the chemical composition and crystalline form and properties of a naturally occurring mineral"
1: ORE 2: an inorganic substance (as in the ash of calcined tissue) 3obsolete : MINE 4: something neither animal nor vegetable 5a: a solid homogeneous crystalline chemical element or compound that results from the inorganic processes of nature broadly : any of various naturally occurring homogeneous substances (such as stone, coal, salt, sulfur, sand, petroleum, water, or natural gas) obtained usually from the ground b: a synthetic substance having the chemical composition and crystalline form and properties of a naturally occurring mineral 6minerals plural, British : MINERAL WATER
Last edited by 1bwana1 on Thu Aug 20, 2020 2:12 pm, edited 1 time in total.
Joined: Sun Oct 16, 2005 12:22 pm Posts: 21602 Location: San Francisco
In order for something to be described as synthetic in the gem world there has to be a naturally occurring counterpart. Synthetic diamond: Natural Diamond Synthetic Sapphire: Natural Sapphire
Artificial product: cubic zirconia. ZrO2 is doped with a calcium oxide or yttrium to stabilize it and have it xlize in a cubic form. Baddeleyite is a naturally occurring ZrO2, but it contains no calcium oxide and crystallizes with a prismatic monoclinic habit. Therefore, CZ isn't a synthetic.
So maybe in order to keep the definition consistent across disciplines, the definition should be updated to something like:
A naturally occurring substance, or synthetically produced equivalent substance....
In any case I think if you use the word mineral alone it implies naturally occurring. You must use the adjective synthetic when referring to a lab made mineral equivalent.
This also plays in the grey area of inorganic when describing minerals vs gemstones. There are a number of organic gemstones. Pearls are an example. However pearls are covered by organically produced layers of aragonite. Is this aragonite a mineral? There is both inorganic and organic origins of the mineral aragonite. Additionally these aragonite layers can form spontaneously in nature, or be cultured by mans intervention. There is quartz that is natural in origin, and quartz that is lab grown in origin.
AS man is more and more capable of inserting itself into the processes of nature, nothing in the World is simple black or white these days it seems.
Joined: Sun Oct 16, 2005 12:22 pm Posts: 21602 Location: San Francisco
Synthetic stones described in the CIBJO Blue Book 4.2.3 Synthetic products are those having essentially the same chemical composition, physical properties and structure as that of their naturally occurring counterparts.
That is why lab grown "opal" is an artificial product, an imitation.
The difference is that lab produced "opals" are impregnated with a polymer which fills the voids/space between the monodisperse silica particles, not silica. Hence, properties like specific gravity, refractive index, hardness and temperature resistance are different.
I think some confusion arises from how geology courses are taught. In geological terms like 'rock' and 'mineral' describe classes of materials rather than individual objects. So you might get corrected by a geologist or enthusiast when you call a mineral specimen a "rock" but that's more a distinction of what class of material it is a good example of. We all agree that a lab-grown crystal of quartz is still quartz, since all properties are essentially the same. We also agree that quartz (as a class) is a mineral, so you can certainly say that lab-grown piece is an example of a mineral, just as a CZ is not an example of a mineral but rather a "mineralloid" (until we find some in nature), and moissanite was reclassified as a mineral when it was finally found in nature. One could certainly call it an arbitrary distinction, which is truem. We're just putting things in convenient boxes, and part of that is the fun of arguing about edge cases. Does that make some "synthetic opals" a mineraloidoid? I'm going to say yes.
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