I have a pretty interesting theory on this. I’ll start from the beginning.
A few days ago I was looking up the prices of emerald jewelry, and the price of emerald per carat (because it’s my birthstone). And because I’m SU trash, I decided to look up the prices of pearls, garnet, peridot stones, etc.
At first, I looked through the prices per carat of all the gems:
Garnet: (Specifically Rhodolite, because it’s the closest to Garnet’s color scheme) $100-400/carat
Pearl: (Specifically oval pearls, since Pearl’s pearl is an oval) $3-10/pearl
Lapis Lazuli: low grade: $1/carat | high grade: $100-150/carat
Peridot: There’s a huge range, but the common range I found was $1-150/carat
Jasper: (specifically orange jasper) $12-50/carat
Rose Quartz: $2.49/carat
So, with all that in mind, I looked up the price/carat of the fusion gems we’ve seen:
Opal: (specifically white opal) $200/carat, up to $2500/carat
Sugilite: lots of results for this one. Anything from $13/carat to $5000/lbs for the high quality stuff
Malachite: $50/carat, or $96/lbs.
Alexandrite: $50,000-1,000,000/carat (yikes)
So now that you have some basic information, here’s my theory.
I think that the gems have a hierarchy based on power, or value. When you look at the basic gems, they all have pretty small prices, but jasper, lapis, peridot, and garnet all have high prices. Also, those gems are very powerful and/or intelligent. (Peridot’s price range can go up to $900/carat, but that’s for extreme high quality stuff).
Also, it seems that when gems fuse, the value, or power of the new gem skyrockets. Alexandrite is a combination of three, well technically 5, gems and can go up to 1mill/carat.
(The only thing that sort of invalidates this is that Garnet is a fusion of Ruby ($2,000/carat) and Sapphire ($350/carat). However, if you take into account the most valuable form of garnet, and not Rhodolite, the top garnet $/carat would be $720-18,240. So maybe it’s still good after all?)
So let’s take this and look at the Diamond Authority. Supposedly, it’s the highest ‘caste’ in the gem society, consisting of gems such as yellow diamond, blue diamond, white diamond, and perhaps others. The prices of those diamonds are ridiculously high. (Yellow diamond: $6,300 and over/carat. Blue diamond:100,000 and over/carat, one was sold for 3.3million. White diamond: $3,080-26,950/carat) Red diamonds can be over $900,000/carat. This shows that the diamond gems are extremely powerful and thus, respected.
This can also tie into a few other things. One being the theory that Rose Quartz was once part of the diamond authority. Perhaps, when she rebelled against the homeworld gems to save the Earth, the Diamond Authority cast her out of their ranks, and she either took on the alias of a very common and cheap stone, or the Diamond Authority sort of took away her title, and made her title, or name, something of a very low gemstone.
The other thing is the reason that Jasper looked down upon Garnet so much for being a fusion.
If you look at the price of Alexandrite, listed above, you can see that is contests with, and even surpasses the value of some of the diamonds I listed. So maybe, the Diamond Authority makes it so fusion is highly looked down upon, possibly even illegal, so gems wouldn’t think about fusing and overthrowing the Authority. More evidence could be provided in the tools that Jasper and Peridot used. Those yellow shocker thingies, remember? (Yes, great name, I know) Jasper used one to actually unfuse Garnet, so maybe those diffusers(?) are used by some sort of 'gem police’ or military to unfuse gems. It was given slight context through the entirety of Jail Break and the episode before (I can’t remember the title of it for the life of me) that Jasper was a sort of bodyguard for Peridot, so it would make sense that she had one. And also, Peridot being so amazingly good with technology, and needing a bodyguard might mean that she’s a really important gem (which would explain why she was trusted with restoring warp pads and all that) and that could make sense of how peridot gems are worth up to $900/carat
So uh, yeah. This is kind of all over the place, but that’s it!