This achievement is obtaned by getting a best weapon by Dragonstones.
Weapon must be at level +3 to start upgrading by Dragon stones.
Weapons must be strengthened by Dragon stones up to a maximum of level 5.
Below are weapons that require the lowest ammount of ore to get final upgrade:
(Shard/Chunk/Pure) Dragonstones required
Iron Knuckles: Dropped by Miners (Fist) in Stonefang Tunnel (15/6/1)
short sword: Sold by Blacksmith Oldwin (20/7/1)
Best places to find Ores:
Dragonstone shard: Dropped by all types of Bearbugs
Chunk of Dragonstone: Dropped by Large Bearbugs, many treasures in Lava 2-2
Pure Dragonstone: Dragon God Archstones, after defeating a Boss 2-3