Jack o'Lantern

Jack 'o' Lanterns (or Jack-O-Lanterns) are solid blocks implemented in the Halloween Update on October 31st 2010. It can be created by combining a pumpkin and a torch. They are intended as a purely decorative addition although they can also be used as a light source.

As with the pumpkin, a Jack 'o' Lantern can be placed anywhere as long as the block directly beneath it is a solid, opaque block; thus, they can be placed at the bottom of lakes or oceans, allowing the user to easily explore underwater areas. However, it will remain in place if you remove the block below it after placing it. They emit light in every direction and the face does not need to be visible to emit light, so it can be very useful in creating hidden lights.

Jack 'o' Lanterns produce the same amount of light (level 15) and share the same ability to stay lit underwater as glowstone, making them more effective and more reliable than torches. Jack 'o' Lanterns will also melt Snow and Ice.

When attempting to push a Jack 'o' Lantern with a piston, it will break and drop as a resource.

Jack 'o' Lanterns can also be used to make a Snow Golem and an Iron Golem, although golems made in this way are no different, aesthetically or functionally, from golems made with regular pumpkins.

History

 * With the Alpha 1.2.0_02 update on November 4th 2010, all Jack 'o' Lanterns on worlds were converted back into Pumpkins in name only.
 * In Beta 1.1_02, Jack 'o' Lanterns are labeled Pumpkins when moused over in the inventory screen.
 * Jack 'o' Lanterns had, up until Beta 1.2, the same icon and name in the inventory as pumpkins, making it impossible to tell which is which just by looking at them. However, it isn't possible to stack Jack 'o' Lanterns with Pumpkins.
 * As of Beta 1.5_01, Jack 'o' Lanterns that already exist in-game now all appear facing the opposite way they were placed before the update. Placing a Jack 'o' Lantern will also have it placed facing away from you, as opposed to facing in your direction, as was the case before the 1.5_01 update.
 * As of 1.8 when farming Pumpkins was implemented, Jack 'o' Lanterns are a renewable resource (provided the player makes their torches from charcoal)
 * In Snapshot 12w08a the Iron Golem can also be made by using Jack 'o' Lanterns.

Trivia

 * Jack 'o' Lanterns cannot be placed on Air, Fences, Glass, Flowers, Mushrooms, Pressure Plates, Sugar Cane, Torches, Redstone Torches, Redstone Dust, Signs, Glowstone, Ice, Pistons, any Stairs, Iron Bars, Slabs or Sticky Pistons.
 * In SMP, Jack 'o' Lanterns appear green on a map.
 * If a player removes the solid block beneath a Jack 'o' Lantern placed underwater, swimming directly beneath it and touching the Jack 'o' Lantern will cause the game to think the player is above water, allowing the player to refill on air without surfacing, also allowing the player to see what is underwater.
 * Jack 'o' Lanterns are useful to create cheap breadcrumb beacons in the nether, because unlike torches they will stay in place even if the netherrack it has been placed on is destroyed, and unless it is directly hit it can often resist ghast bombs explosions, unlike glowstone blocks. Also, it stands out more than glowstone beacons because it cannot be found naturally. It is also better than fire, because extended fights against ghasts will often leave the landscape torn apart and burning everywhere.
 * Despite presumably containing a torch as their light source, Jack 'o' Lanterns emit more light than torches.
 * Unlike pumpkins, Jack 'o' Lanterns cannot be worn on your head
 * Jack 'o' Lanterns are the only self contained light source that minecart Rails can be placed on.