Poliwhirl's Gem Tier List
incomplete but still semi-insightful gem power rating, based on the punch power segment in know your fusion:
top is weakest, bottom is strongest
Pearl
Stevonnie
Smoky
Garnet
Opal
Sugilite
what can be assumed based on what we've seen in the show thus far and the above ranking
(again top is weakest, bottom is strongest)
Peridot (could easily rise once her powers grow)
Ruby / Sapphire (individually)
Steven (could rise as well, close to tying with amethyst)
Amethyst
Pearl
Jasper
Stevonnie
Smoky
Rainbow Quartz (not much is known, so this is iffy. possibly below smoky.)
Bismuth (seen sparring with garnet and holding her own, but i doubt she could survive angering garnet)
Garnet
Opal
Lapis (stole the entire ocean, and created powerful clones of the people she was fighting. however, she relies on being close to a body of water, which is the only thing stopping her from being right up their in the god tiers.)
Sardonyx (3 gems in one, to be fair)
Sugilite
Malachite (in the incredibly unlikely chance that jasper and lapis work together, because crazy water powers)
Alexandrite (beat malachite in a fight, but that was only because the watermelons distracted her. if alexandrite trained consistently she probably would have beaten malachite without help. possibly tied, though.)
A cleaner version without explanations and with echelons:
Situationally Useful
18. Peridot
17. Ruby
16. Sapphire
Decent Figthers
15. Steven
14. Amethyst
13. Pearl
Notably Strong:
12. Jasper
11. Stevonnie
10. Smoky
Powerful
9. Rainbow Quartz
8. Bismuth
7. Garnet
Incredibly Powerful
6. Opal
5. Lapis
4. Sardonyx
God Tier
3. Sugilite
2. Malachite
1. Alexandrite