Silk Touch causes certain items to duplicate

When using silk touch on certain items they are duplicated.

• Ender Chest: Returns 1 Ender Chest and 8 Obsidian
• Dropper: Returns 2 droppers
• Dispenser: Returns 2 dispensers
• Furnace: Returns 2 furnaces
• Cauldron: Returns 2 Cauldrons
• Noteblock: 2 Noteblocks
• Jukebox: 2 Jukeboxes
• Beacon: 2 Beacons

There may be more.