I think I'd add something to his dissertation, however: remember the names of the stones you sell! We who use these stones in necklaces and bracelets need to be able to let our potential customers know what we've used in a design. Maybe we don't need to go into the detailed explanation Silver Bear did but we still need to let them know "Hey, this is quartz versus actual amethyst" or vice versa. To that end, those of you we buy from need to be sure you correctly label the stones you sell.
As an example, there's a lady in my town who owns a bead and yarn store. It's like walking into Aladdin's Cave she has such wonderful things! BUT! Some of her stones aren't labelled. I asked about one I was interested in, it had a great color and pattern but no name label. Chances are, according to Silver Bear's post, it was some form of quartz. Regardless, her reply was "Oh, I don't know. I buy stones I like and don't always get the name." Uhm, sorry, but that's bad business in my book. If I don't know what a stone is, I'm not buying it since I can't tell potential customers what they're getting (leaving it at "quartz" is lazy in my book, I'd want to know what kind of quartz before I bought from someone). So, that day, she lost a potential sale on that particular stone. She actually has lost a lot more in the sales department from me. She really hikes the price of her wares and I think it's because she needs to read Silver Bear's article. Not every stone with a fancy name and huge price tag is worth the money.
It's like buying a car, folks. Do your own research. Don't buy just because you HAVE to have it (and might never find it again! gasp!) or it's pretty or unusual and the high price must indicate it's quality. There are always variations on that particular stone out there. Learn about the stone before you buy. You'll save yourself, and any future customers, a bundle of money. Not to mention that, if you have a savvy customer who researches before buying and they know that particular stone isn't worth the $50.00 price tag slapped on it...? You lose out on 1) them wanting to buy anything else from you... if you overcharge for what they know is worth only $20.00 what else have you over priced? 2) you lose out on the money you paid for an over priced stone to begin with. And, 3) you lose out on word-of-mouth. It works for bad as well as good. Do you want people to tell others "Oh, buy from so-and-so on Etsy (or wherever)! They have great products and great service!" or do you want them to say "Well, they have a great looking product but the prices for the items they sell? Yeah... well, it's up to you but I wouldn't pay that much for simple quartz."
Educate yourself before the fact. Don't lose customers because they knew what you didn't.