Good thing I wrote the stats on a piece of paper.
Diamond: Weapon Attack [1, 2, 3]
Sapphire: Magic Attack [1, 2, 3]
Garnet: Accuracy [2, 3, 5]
Opal: Avoid [2, 3, 5]
Aquamarine: Jump [1, 2, 3]
Amethyst: Speed [1, 2, 3]
Topaz: HP [10, 20, 30]
Emerald: MP [10, 20, 30]
Black Diamond: Random [1, 2, 3]
Dark Crystal: Random [2, 3, 5]
Power Crystal: STR [2, 3, 5]
DEX Crystal: DEX [2, 3, 5]
Wisdom Crystal: INT [2, 3, 5]
LUK Crystal: LUK [2, 3, 5]
Secret Crystal: Level Requirement [-1, -2, -3]
That's all I have. The numbers between [ ], depends on the grading the jewel has. So if you use a High Graded Diamond while forging, your weapon will have +3 Weapon Attack; if you use a Low Graded Topaz, whatever you made will have +10 HP.
Also, I don't know if this was mentioned, but you can only forge stuff that's like standard equipment. No Maple Weapons, no Shinobi Bracers, none of that kinda stuff.
Diamond: Weapon Attack [1, 2, 3]
Sapphire: Magic Attack [1, 2, 3]
Garnet: Accuracy [2, 3, 5]
Opal: Avoid [2, 3, 5]
Aquamarine: Jump [1, 2, 3]
Amethyst: Speed [1, 2, 3]
Topaz: HP [10, 20, 30]
Emerald: MP [10, 20, 30]
Black Diamond: Random [1, 2, 3]
Dark Crystal: Random [2, 3, 5]
Power Crystal: STR [2, 3, 5]
DEX Crystal: DEX [2, 3, 5]
Wisdom Crystal: INT [2, 3, 5]
LUK Crystal: LUK [2, 3, 5]
Secret Crystal: Level Requirement [-1, -2, -3]
That's all I have. The numbers between [ ], depends on the grading the jewel has. So if you use a High Graded Diamond while forging, your weapon will have +3 Weapon Attack; if you use a Low Graded Topaz, whatever you made will have +10 HP.
Also, I don't know if this was mentioned, but you can only forge stuff that's like standard equipment. No Maple Weapons, no Shinobi Bracers, none of that kinda stuff.