Gem Identification for Dummies

Beryl but not emerald

Everyone dreams of striking it rich for little or no work – that's the reason why there are slot machines and state lotteries, after all. Besides the many folks who think maybe they could wander over to the nearest mountain and pull out large lumps of gold, there are also apparently people who believe that finding precious jewels is a matter of going for a hike and keeping a sharp eye. That's what eHowian Matt V. thought, anyway, before the Leaf Group cleanup team got a glimpse of "How to Identify Rough Gem Stones" and sent Laurie Brenner (formerly Laurie Reeves) in to spruce it up.

Brenner, whose bio explains her expertise as, "[a] stint as Manager of the California State Mining and Mineral Museum," launched into a primer on mineral identification. She nibbled around the edges of crystal shape by claiming that "Minerals fall into five basic shape categories," listing Massive, botryoidal, reniform, tabluar, and acicular. In point of fact massive, botryoidal and reniform refer to the shape of mineral aggregates, not to the minerals themselves. So much for "shape."
Brenner then harped briefly on mineral streak, telling her readers that,

"...the hematite stone is black when polished, but it leaves a red streak across unglazed porcelain or ceramic."

Out staff geologist shuddered at the construction "hematite stone," since hematite is a mineral... But, then, Laurie the journalist is the expert, not some guy with a couple of degrees in geology. Next, we learn to inspect the luster, then the cleavage, of which Brenner rattles off bogosity like,

"Flat flakes break in one piece... Rhombic breakage occurs on several planes at diagonal angles... Long blocks result in breakage in two planes..."

We ain't gonna touch that except to say it's utter bull. And we won't even try to disabuse the woman of her notions of mineral color.

What we will do, however, is point out that Brenner did her readers a great disservice by prattling about gems. Instead, she should have started by explaining that gemstones are, by and large, exceptional specimens of more "ordinary" minerals. If you want to find emeralds, for instance, you look for beryl; to find sapphires and rubies, hunt for corundum.

Maybe our Dumbass of the Day should have started there...

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