The Double Crusher works on two items at the same time.
Gold Ore → 2 × Raw Gold
Golden Horse Armor → 6 × Raw Gold
Gravel → Flint + Flint (50%)
Iron Horse Armor → 6 × Raw Iron
Iron Ore → 2 × Raw Iron + Raw Gold (20%)
Lapis Lazuli Ore → 12 × Lapis Lazuli
Lilac → 4 × Magenta Dye
Lily of the Valley → 3 × White Dye
Nether Quartz Ore → 3 × Nether Quartz
Orange Tulip → 3 × Orange Dye
Oxeye Daisy → 3 × Light Gray Dye
Peony → 4 × Pink Dye
Pink Petals → 3 × Pink Dye
Pink Tulip → 3 × Pink Dye
Pitcher Plant → 4 × Cyan Dye
Poppy → 3 × Red Dye
Prismarine Shard → Prismarine Crystals
Red Tulip → 3 × Red Dye
Redstone Ore → 10 × Redstone Dust
Rice Plant → 2 × Sugar
Rose Bush → 4 × Red Dye
Sugar Cane → 3 × Sugar
Sunflower → 4 × Yellow Dye
White Tulip → 3 × Light Gray Dye