Ore

In the volcanic land of Subrosia, there are many types of special, prized stones called Ore. There are six different types of ore: Red and Blue, Hard Ore, Star-Shaped Ore, Fool's Ore, and Ore Chunk, the latter of which is Subrosian currency in Oracle of Seasons.

Ore Chunks
The Ore Chunk is the standard currency of Subrosia, replacing the common Hyrulean Rupee, due to its abundance and symbolic worth in Subrosian culture. Link can carry up to 999 Ore Chunks while in Subrosia. The currency exchange rate between Holodrum and Subrosia is 1 Rupee to 1 Ore Chunk; the type of currency is the only monetary change between the two regions. When equipped with the Green Joy Ring or Gold Joy Ring, Link will receive double the value of Ore Chunks gathered.

Blue Chunks set the currency standard, as there is no smaller denomination of money in Subrosia. One Blue Chunk represents one Ore Chunk. Red Chunks are worth ten Ore Chunks (ten Blue Chunks). Gold Chunks are worth fifty Ore Chunks (five Red Chunks, or fifty Blue Chunks).

Other Ores
Star-Shaped Ore can be found among the sands of the Subrosian beach. Link can trade it at the Subrosian Market for a Ribbon, which Link's need to gift to Rosa in order for her to go on a date with him.

Red and Blue Ore is taken to the Great Furnace in Subrosia, where Link can have them melted together to produce the Hard Ore.

Hard Ore is made when the Red Ore and Blue Ore are combined at the Great Furnace. Link can then take the Hard Ore and Wooden Shield to the Subrosian Smithy where the two can be forged together to make the Iron Shield.

Fool's Ore is left in place of Link's Roc's Feather after the Strange Brothers steal it. It can be used like an item, but it serves no function. When Link reclaims his Roc's Feather, he drops the Fool's Ore.