From YPPedia

Masuyite
Raw goods
Mass: 5.1 kg	Volume: 1 L
Obtained from: Merchant Brigands, Commodities markets
Used by: Iron mongers, Shipyards, Furnishers
End products: Bludgeons, Swords, Furniture

Masuyite is one of eleven minerals. It is an ingredient in bludgeons and swords. It can only be found on one island in each ocean,except the Midnight Ocean and the Malachite Ocean. Expect it to be expensive at a Commodities market.

German article: Masuyit

Spawn Locations

Cobalt	Hunter	Ice	Malachite	Midnight	Sage	Viridian
Labyrinth Moors	Umbarten Island*	Winking Wall Island*	Cenote Island* Lilac Island Mu Abtu*	Meke Island O'Reilly Island*	Kakraphoon Island	Labyrinth Moors

*Islands without market bidding.

Use

Masuyite is needed in the production of:

Furnisher products

Fireplace (1)

Pot Bellied Stove (2)

Iron monger products

Cutlass (2)

Falchion (3)

Scimitar (3)

Shipyard products

Brass Knuckles (1)

Hammer (3)

Skull Rings (4)

Real World Counterpart

Masuyite is made from the elements Uranium, Hydrogen, Lead, and Oxygen, by the chemical formula Pb[(UO₂)₃O₃(OH)₂]·3(H₂O). This mineral is radioactive in reality. This is based on the data from http://webmineral.com