E is for Emerald

[Justme]

Sigh...guess I got all the precious stones out of the way.
3.5*
This story was about a Scarlet Emerald, which I have learned is more rare than the rarest diamonds, also red. None of which is mentioned in the book.

"Red beryl (aka bixbite, "red emerald," or "scarlet emerald") was first described in 1904, and while it is closely related on a chemical level to both emerald and aquamarine, it is considerably rarer than both. (The mineral's red color is due to the presence of Mn3+ ions.)

The mineral's known distribution is limited to parts of Utah and New Mexico, and has proven exceptionally difficult to mine in an economically feasible fashion. As a result, some published estimates say rubies of similar quality (rubies being a rare gem, themselves), are roughly 8000 times as plentiful as any given red beryl specimen. Consequently, prices on red beryl have been known to reach as much as 10 grand per carat for cut stones."

[Justme]

I was pretty sure I'd learned this years ago, but looked it up:
"Emeralds are not as durable," he says. "They have natural cleavage planes and it might break. It's not about scratching, it's a chipping issue. An emerald is rarer than a diamond by far, and large emeralds are very expensive and exceed the costs of diamonds, but they don't have the same ability to take wear and tear."