Java Edition:Lapis Lazuli Ore (Item)
Lapis Lazuli Ore was added in Beta 1.2 but the item form for the block was not normally obtainable until Beta 1.9 Prerelease 4 with the introduction of Silk Touch. Lapis Lazuli Ore as item could be obtained before being recontinued through Indev conversion and in debug chests of Beta 1.6 Test Build 3. This item was again discontinued for only one version, 12w32a, in which Silk Touch doesn't work.
Obtaining
Indev Conversion
Indev Item Conversion
Red cloth from Indev had a numeric ID of 21, identical to Lapis Lazuli Ore. If red cloth is left in a chest and converted to Beta 1.2, it'll convert to Lapis Lazuli Ore. The conversion only occurs if the chest containing the item is not opened until Beta 1.2 or later, otherwise it'll cause the game to crash.
Beta 1.6 Test Build 3 Debug Chests
Beta 1.6 Test Build 3 Debug Chests
In Beta 1.6 Test Build 3, any newly generated world would contain up to 11 debug chests with every item in the game. The Lapis Lazuli Ore item was obtainable in the chests 1st and 5th from the left in the 21st and 5th slots respectively, in stacks of 64.
1st Beta 1.6 Test Build 3 Chest
5th Beta 1.6 Test Build 3 Chest
Silk Touch
From Beta 1.9 Prerelease 4, Silk Touch was introduced allowing players to get blocks they couldn't get before. All a player has to do to obtain the item form is to mine a lapis lazuli ore block using a Silk Touch pickaxe. This doesn't work in 12w32a due to a bug.