Soul Stone

Sell value
30 Gold

What drops it

 * Shiro'ken

Common crafting materials

 * 3-4 Granite Slabs

Rare crafting materials

 * 1 Lump of Charcoal

Testing
In a trial of 50 Soul Stones salvaged using a Superior Salvage Kit, 162 Granite Slabs and 6 Lumps of Charcoal were produced. A loss was recorded: for maximum profit, just sell them to the merchant.