Mineral name wise, sapphires are a type of corundum. Usually blue, sometimes green, yellow, orange, or others, depending on various metals mixed into it. But if it’s red (via chromium) it’s a ruby instead.

Clear crystalline aluminum oxide you’d generally just call corundum (or aluminum oxide if you’re not feeling fancy), but that doesn’t market as well when you’re making watch faces and camera lenses out of it, so I guess we’re calling that sapphire now too.

TLDR: Gemstone naming seems a bit super arbitrary and marketing driven (not that I’m an expert on the subject)

The names ruby and sapphire are not marketing driven; they are color terms that long predate the development of chemistry to the point where we could determine what gems were.

Many famous historical "rubies" are not corundum but spinel; they were called rubies because "ruby" was the term for any red gemstone.

"Moissanite" is purely marketing, though.

I can also verify this. I currently have 932 flawless imperial rubies in my stash and they are all red.

One of the drawbacks of being dragonborn is the hoarding instinct.

Proudspire Manor won’t buy itself

Looks like a Diablo 3 reference to me. Put one of those in your hat for +37% exp!

:)

Sadly, I do not personally own any historically significant jewelry. But you can read about it pretty easily.

https://en.wikipedia.org/wiki/Black_Prince%27s_Ruby

> The Black Prince's Ruby is a large, irregular cabochon red spinel weighing 170 carats (34 g)

> It wasn't until 1783 that spinels were differentiated from rubies.

Well, all non-red corundums are called "sapphire" - with qualifiers for anything that isn't blue (all those yellow and pastel colors, which are all called "fancy sapphires"), and a special exception for pinkish-orange, which are called padparadscha[1].

1: https://en.wikipedia.org/wiki/Sapphire#Padparadscha

Not all red sapphires are rubies--ruby describes "pigeon blood blue" red color. There are also ceylon sapphires that range from pinkish to fire-engine red through burnt orange in color.

Yep, I'm aware. I've always felt that the material should embrace what it is -- a crystalline material allowed by nature but manufactured by experts [1] -- rather than attempt to meet naturally-occurring gemstones on their turf. (Yes, crystalline SiC has been found in nature as moissanite, but it is exceedingly rare.)

For some people, geologists in particular, there is a romance to the formation of a natural diamond due to heat and pressure within the earth. That's great too!

[1] Look at your high-efficiency LED lights to find some SiC in your house. Thanks, Cree and others!