Get some Amethyst, Dummies!

Amethyst crystals

Our science team members run across more than a few people who ascribe magical powers to crystals during their research. We tend to avoid that content like the plague, mainly because we're not in the habit of trying to debunk metaphysical claims, though we're perfectly happy to point out a writer's innate dumbassery whenever they start making errors of fact. Sometimes, people are just trying to sell their products – that seems to be the case with Eric Jhonson [sic] of DailyTwoCents.com, who's penned a series of articles about gemstones that are... somewhat suspect. Given that Jhonson's bio says he's "an accomplished writer," we figured anything he says is fair game,  so we're taking on "Amethyst Gemstone: All That You Ever Wanted to Know."¹ Does Eric elucidate? or just advertise his goods on some auction site called LiquidationChannel.com?

Well, it seems to be mostly the latter: of Eric's 13 posts to the site, all have been splattered with oversized images of his jewelry, links to the auctions carefully encoded in the "photo credit." As long as you know... what we're here for is to see if Jhonson can deliver "all that you ever wanted to know" about amethyst. First things first: what's the chemical composition of amethyst? Bzzzzt: not there (strike one). For the record, it's just purple quartz, SiO₂. Jhonson also doesn't bother to explain where the mineral gets its coloration, since common quartz is generally clear or white. Hint: chemical impurities...

Second, how does amethyst form? The best Jhonson can come up with is

"Many different scenarios give 'birth' to this amazing gemstone. This colourful gem occurs in igneous and metamorphic rocks, especially in granite and gneiss. Clastic sediments also hold it. The cavities from porphyries and pegmatites also have contained some top quality amethyst. As the gem resists weathering, it is also found in alluvial sands and gravels."

Well, that's true of quartz in general. We don't know of any amethyst-bearing gneiss, though such a thing is certainly possible. For the record, however, neither porphyries nor pegmatites generally have "cavities." No, the most common source of amethyst crystals is the lining of fissures such as joints and cleavage. You do find large amethyst grains in pegmatite, but as interlocking grains with other large crystals (strike two). Eric follows with utter bullshit about identifying the source of your amethyst: "It will be interesting to note here that this gemstone from each source comes with its exclusive features and as such it is possible to decipher the mine and location of each specimen if one observes it carefully." Well, no. Jhonson follows this rubbish with examples of exactly two unusual samples that display what he calls a "'phantom phenomenon" and a mineralogist would call a "zoned crystal." That's it. Maybe with a worldwide catalog and a mass spectrometer you could identify the source but "careful observation"? Give us a break!

Finally, Eric "informs" his readers -- potential customers -- that

"The color of the stone, though rich purple, is feeble and can lose its shine if exposed to sunlight for a longer duration. It will be interesting to note that citrine, the yellow variety of quartz and a gem that is not easily available, is produced by heat-treating amethyst."

Overexposure to ultraviolet light can, indeed, cause amethyst to fade. But Jhonson's comments about citrine should be taken with a grain of salt: amethyst can be created and darkened by irradiation of common quartz, but only natural amethyst can be heat-treated to make a low-quality form of citrine. That's not to mention that citrine is also a naturally-occurring mineral.

We couldn't complete our analysis of Eric's content -- remember, he's an "accomplished writer" -- without taking a look at some of the descriptions. Given that it's amethyst, we suppose we can forgive him the purple prose (rim shot):

"...violaceous stone... incredible gem... lively stone... amazing gemstone... riveting color... colorful and lustrous beauty..."

Ugh. No, Eric didn't tell us "all that [we] ever wanted to know." He didn't say anything about its composition or what causes its color. He merely reworded the wikipedia entry for amethyst to explain the name, and he got quite a bit of the mineralogy wrong (not to mention that drusy minerals are too small for jewelry work). For getting it wrong and for insulting Roget, we hereby award Eric Jhonson the Antisocial Network's Dumbass of the Day. Unfortunately, there's no amethyst on the award...

¹ The site is now defunct, but you can still see the post using archive.org's Wayback machine. Its URL was   dailytwocents.com/amethyst-gemstone-all-that-you-ever-wanted-to-know/

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