Requirements for Acuman on SOM

I want to put acuman on my SOM but never done an A grade weapon. I have the SOM and crystal. Do i need anything else and where do i do it?

Besides the stage 12 crystal (blue? not sure) you need Gemstone A. 157? 143? Forgot about it. Take both and your weapon to the Blacksmith of mammon.

Thx for that but where do i get the gemstones?

Player stores or Merchant of Mammon. Mammon takes 30k AA iirc.

To put Acumen on a SoM you need.
x1 Sword of Miracles.
x140 gemstone A grade
x1 Stage 12 blue Soul Crystal

You get the Gemstone A's from Either player shops(usually over priced) or the Merchant of Mammon. From the merchant Each gemstone costs 30,000 Ancient Adena.