NFT Rank Purity

The NFT ranks have an attribute called Purity. This affects its use and increases or decreases the rewards multiplier.
Gold NFT
Diamond NFT
Emerald NFT
Obsidian NFT
Gold Rank NFT
Purity Rank
Earning multiplier
Very Low { 0 - 10% }
x4
Low { 10% - 30% }
x4.5
Average { 30% - 70% }
x5
High { 70% - 90% }
x5.5
Perfect { 90% - 100% }
x6
Diamond Rank NFT
Purity Rank
Earning Multiplier
Very Low { 0 - 10% }
x8
Low { 10% - 30% }
x9
Medium { 30% - 70% }
x10
High { 70% - 90% }
x11
Very High { 90% - 100% }
x12
Emerald Rank NFT
Purity Rank
Earning multiplier
Very Low { 0 - 10% }
x16
Low { 10% - 30% }
x18
Average { 30% - 70% }
x20
High { 70% - 90% }
x22
Perfect { 90% - 100% }
x24
Obsidian Rank NFT
Purity Rank
Earning multiplier
Very Low { 0 - 10% }
x26
Low { 10% - 30% }
x27
Average { 30% - 70% }
x28
High { 70% - 90% }
x29
Perfect { 90% - 100% }
x30
Is there a way to increase the NFT's Purity?
When forging a rank there is a probability of increasing its purity by up to 5%.