Malachite Ocean was the fifth doubloon ocean and was opened on 2008-5-6. The ocean has fifty-five islands distributed among eight archipelagos - twenty-five outpost islands, twenty-five medium islands, and five large islands. There are three small archipelagos of three islands, each with one outpost island and two medium islands, four large archipelagos of nine islands, each with four outpost islands, four medium islands and one large island, the archipelago capital island, and lastly one archipelago of ten islands, containing six outpost islands, three medium islands, and one large island. Malachite, along with the Viridian Ocean was merged into the Meridian Ocean on 31 Jan 2012.
The ocean's name comes from Malachite, a green copper-based mineral with the chemical formula Cu2CO3(OH)2. The name may also come from Malachite green, a highly toxic pH indicator - the indicator is green in neutral solutions, but turns yellow in highly acidic environments (pH < 2) and colourless in basic (pH > 12 ). It is so toxic that it is banned in many countries.
The archipelagos in the ocean are named after lizard species and genera. The islands in each archipelago are named with some theme in mind - for example, the islands in the Basilisk Archipelago are named after real-world oceans, while the islands in the Draco Archipelago are named after mythological creatures.
Compared to the other oceans, the Malachite Ocean is more compact and dense - though it has the second greatest number of islands for any ocean (second only to the Midnight Ocean), it also has the second fewest number of league points (second only to the Ice Ocean, which also has the fewest number of islands).