YES, IT’S GLASS – MISCONCEPTIONS ABOUT MOLDAVITE, THE METEORIC GLASS
Let’s demystify moldavite (frequently misspelled as moldivite and moldevite). In the simplest definition possible, it is a green glass originating from a meteor that hit the Earth 15 million years ago. It is not a crystal, rock, or synthetic. It is a naturally occurring mineral (although not from Earth) that is limited in quantity.
But there is much more to moldavite than this simple explanation. There are lots of misconceptions surrounding it as is the standard in the ironically named information age.
WHY IS MOLDAVITE NOT A CRYSTAL OR ROCK?
To answer this question, we need to know what crystals and rocks are.
Crystals in the scientific definition are solid materials with highly structured geometric lattices. Too technical? Basically, quartz is made up of repeating, distinct, and organized patterns of molecules.
Glass, which is a solid, is amorphous. This means without a defined shape or form. If you could see the molecules of glass, you would not see repeating, distinct, and organized patterns. The molecules would be jumbled up and without any clear meaning.
Moldavite is not crystalline. It was made up of crystalline materials and rock that melted and formed moldavite, however. But because it by itself is not crystalline, yet is a solid, amorphous material, we call it a glass.
What about liquid crystal like in LCD? Aren’t crystals supposed to be solid?
Liquid crystal is something of a misnomer, but a helpful one. In reality, liquid crystal is weird. It is fluid, like liquid, but exhibits many properties of a crystalline solid (chiefly optical). If you’re familiar with the four states of matter (solid, liquid, gas, and plasma) you may be shocked to hear that liquid crystal is another one. In fact, there are way more intermediate states of matter (“in-betweens”) like liquid crystal.
Without getting too deep in advanced physics, let’s leave it at that moldavite, although exhibiting some crystal-like properties is not actually a crystal.
Are rocks crystals? The answer is no. They are made up of crystals, minerals, and mineraloids. If a rock consisted of only one of these materials, then it would simply be that material!
Here are the quick definitions and summaries if this got too technical or confusing:
Mineral – solid crystalline material with the exact same chemical composition
Glass – amorphous solid with potentially different chemical composition
Rock – aggregate of minerals and/or mineraloids
WHAT IS SYNTHETIC MOLDAVITE?
The question of moldavite being a synthetic or volcanic material is not new. In fact, it was an old academic debate. Friedrich Berwerth in his “Can Moldavite be interpreted as an Artifact?” posited the idea that moldavite may not actually be of meteoric origin. Even a mineralogist working for the US government in the late 19th century was sure that moldavites were just “worn pieces from an ancient glass factory.”
Imitation moldavite was known to exist in the 19th century. A study of five sets of moldavite jewelry at the Museum of Decorative Arts in Prague revealed all but one to be imitation.
The theory that all moldavite was a synthetic, ancient piece of glassware was debunked by thorough chemical analysis. Only a handful of people far removed from the mainstream support the ancient glass theory in present times.
Yet, there is paranoia that every piece of moldavite is synthetic today. A quick Google search of “fake moldavite” for the website Reddit alone gives over two-thousand results.
If you’re wondering if you’re piece of moldavite is fake you should not go to Reddit or other websites. It is almost impossible to tell from a picture if moldavite is fake or real.
Arguably, there are only a couple of differences that can be seen with the unaided eye: shape and gloss. Synthetic moldavite is often, although not always, unusually lustrous. If the shape of the moldavite is too perfect then it may be a fake. Lastly, if the piece is very large or heavy (above 100 grams) then it could be a fake.
Note, that nothing about shape, luster, or size is a sure thing. Imitations can replicate the luster of moldavite rather well and not every imitation is exceptionally large or perfect in shape. But, if you do have a round, 180 gram piece of moldavite with a glossy sheen, there is a good chance it is fake.
More realistically, imitation is near indistinguishable from real moldavite in the modern day. In fact, without a jeweler’s loupe and/or equipment, you cannot tell the difference between fake and real moldavite.
If you have a loupe, there is one way to make a distinction. Real moldavite, faceted or raw, has lechatelierite. These dark, thin inclusions are always present in real moldavite and it is impossible for imitation pieces to replicate them well, if at all.
Bubbles are not a great indicator because not only can imitation moldavite have bubbles, but many bubbles are also near microscopic. Still, fake moldavite more often than not has fewer bubbles than real moldavite.
If you can do a refractive index test, then you may be able to tell the difference as imitation moldavite almost always has a higher RI than real moldavite.
Again, it is encouraged that you do not ask people on the internet to look at your stone and make a judgment call on whether it is fake or real because it is difficult to tell without the proper equipment or knowledge.
Let’s do a quick recap. Moldavite is a glass because it is an amorphous solid with an inconsistent chemical composition. It is not always synthetic as previously thought, but a naturally occurring material from the Ries impact.
It is difficult, if not impossible, to tell the difference between fake and real moldavite so long as they are superficially similar. Without the ability to perform refractive index tests, study a specimen with a loupe/microscope, or fluorescence tests, you cannot easily distinguish a real piece from a fake. Even then, imitations are becoming more like real pieces over time.
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Hanus, Radek & Hyršl, Jaroslav. (2017). Distinguishing "Synthetic" and Natural Moldavite. 10.15964/j.cnki.027jgg.
Hanus, F.. On Moldavites from Bohemia and Moravia. United States, National Aeronautics and Space Administration, 1964.
Hyršl, Jaroslav. Moldavites: natural or fake? GEMS & GEMOLOGY, VOL. 51, NO. 1, pp. 68–110, http://dx.doi.org/10.5741/GEMS.51.1.68
Lower, Stephen. “Liquid Crystals.” Chemistry LibreTexts, 15 Aug. 2020, chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook_Maps/Supplemental_Modules_(Physical_and_Theoretical_Chemistry)/Physical_Properties_of_Matter/States_of_Matter/Liquid_Crystals.
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