Reviewed 22 September 2026
Patterns, fades, and Case Hardened: the seed sets the price
Same name, same wear, different pattern seed: you are looking at two different items.
What the pattern seed does
Case Hardened, Fade, Doppler and a few other finishes sell on seed above all. A scarce one wearing worse condition can outsell an ordinary one in Factory New.
The seed is handed out by Valve when the item is created. Across most finishes it shifts the texture only a little, so wear still decides the price.
Case Hardened blue gems: check which side you are paying for
The finish blends blue, gold and silver. Collectors pay for broad blue areas, mostly on whichever flank of the gun is visible in play. Best known is the AK-47 Case Hardened, where a blue gem on the playside and one on the backside are separate seeds. Any guide rating only one flank will misjudge the other.
Tier lists carry no official weight and move whenever collectors argue. Seeing a screenshot is not the same as knowing the seed.
Downside: gem prices hang on the seed, which a thumbnail cannot prove. Compare the listing's pattern index with a full inspect before you pay, and pick your side first.
Fade percent comes from the community, not from Valve
Nothing on the item shows a Fade percent. The community derives it from the seed: the higher the number, the smoother the gradient and the less flat color remains. Players grade the Glock-18 Fade this way. With a float range of only 0.00 to 0.08, nearly all copies sit in Factory New, so percent sets the price.
A Doppler phase is a look, not a wear
One Doppler name covers several phases. Phases 1 to 4 pair black with pink, blue or green, while Ruby and Sapphire are the all-color specials and Black Pearl is the dark rarity. Gamma Doppler is a separate finish with Emerald as its special and no Ruby or Sapphire. For a quick view of the split, see the Karambit Doppler page.
Wear does not change a phase, so Phase 2 in Minimal Wear is still Phase 2. A seller may crop the inspect image until a dark phase looks like Sapphire.
Downside: a cropped inspect can conceal the true phase. Buy the seed, not the thumbnail.
Questions
What is a blue gem in CS2?
A Case Hardened seed whose blue area is unusually big. Its score is a tier set by the community, with no official rarity behind it.
Is Fade percent official?
No. Players work it out from the seed, and the item itself shows no such number from Valve.