Jewel scaling inconsistency

[TW84]

It's because it's not a round number increment

Diamonds increment at 2.65, so : 7, 9.65, 12.3, 14.95, 17.6, 20.25, 22.9, 25.55, 28.2, which rounded to nearest whole number is 7, 10, 12, 15, 18, 20, 23, 26, 28

Could be, but where is it mentioned?

not to mention the new chaos jewel too, it has 0.2 damage increment until noble (1.85), but exquisite is 2.00 (only 0.15 increase)

Oh I forgot chaos jewel lmao..