An oyster has a chance to contain an oyster pearl, oyster pearls, or nothing. They can sometimes be obtained by fishing with a big fishing net (requires 16 Fishing) or through panning at the Digsite. They can also be obtained as a drop from various monsters. The pearls found from an oyster can be made into pearl bolt tips at level 41 Fletching by using a chisel on them.
Dropping monsters[]
Monster Combat level Quantity Rarity Rock Crab 13 1; 2 Common Sand Crab 15 1; 2 Common Ammonite Crab 25 1; 2 Common Mudskipper 30; 31 1 Common River troll 14; 49; 79; 120; 159 1 Uncommon Dagannoth spawn 42 1 Uncommon Mogre 60 1 Uncommon Cave kraken 127 1 Uncommon Crab 21; 23 1; 2 Uncommon Giant lobster 45 1; 2 Uncommon Waterfiend 115 1–3 Uncommon