Glowstone

Glowstone (formerly known as Lightstone, Brittle Gold, Brightstone, Brimstone or Australium) is a golden block that glows indefinitely. This block can only be found naturally in The Nether. It generates on the undersides of Netherrack, and forms unusual coral-like stalactites. Glowstone has a luminance of 15.

Glowstone can be difficult to harvest, due to high ceilings, sheer cliffs and abundance of lava in the nether. One method of mining it is pillaring up to the deposit and extending the top of the column beneath it to make a platform. Mined dust will fall onto the platform, allowing for easy collection.

Breaking this block drops 2-4 pieces of Glowstone dust, which may be used to re-craft the Glowstone blocks or to boost the effect of a potion. Unlike torches, it isn't destroyed by water and continues to emit light even when submerged like Jack-O-Lanterns. Like all non-sunlight light sources, Glowstone blocks will cause nearby snow and ice to melt.

Uses
Glowstone is an infinite light source and has a higher light level than Torches (15 as opposed to 14.) Because it is a block, players often make ceiling lights and lamp posts out of Glowstone by combining it with a Fence block. Glowstone blocks can also be used as lit paths, due to their interesting texture, or in docks or harbors so users in boats can see where to stop, as it can be placed in water.



Trivia
However, Notch stated that lanterns were not going to be added to Minecraft at Minecon 2011.
 * As of the beta 1.6.6 update, the tool used to extract Glowstone Dust changed from a sword, when it acted like a glass type block, to a pickaxe, as it was then a stone type block. In the same update, the amount of Glowstone Dust needed to craft a Glowstone Block changed from nine to four, and the amount of Glowstone Dust dropped after destroying a Glowstone Block changed from 1 to a range of 2 to 4. in the 1.0.0/RC2 update, Glowstone returned to being a glass type block.
 * When you break a Glowstone block, it makes the same sound as breaking a glass pane.
 * Another way of collecting glowstone is to redirect a Ghast's fire ball at a Glowstone deposit, destroying the blocks with the resulting explosion. This could be useful if the Glowstone is very hard to reach.
 * It is more efficient to harvest Glowstone using Silk Touch Enchantment, since one block is equivalent to four Glowstone Dust, which usual harvesting is more likely to drop less than mentioned.
 * Beta 1.9 Pre-release 5 changed Glowstone's texture from: Glowstone Block-Pre Beta 1.9pre5.png
 * Since Glowstone Blocks become entities when pushed by pistons, this momentarily stops it from giving off light.
 * Glowstone can be found in very large deposits, one of the largest recorded is over 97 (on some non-official servers running 1.8.1 130+ block deposits have been recorded) blocks with +420 glowstone dust dropped.
 * Glowstone's glow, when seen on End Stone, appears to move in and out.
 * Rarely, Glowstone can be found touching the ground if the ceiling it was generated on was extremely low (2-3 blocks of clearance).
 * When glowstone is placed 9 or more blocks above ground level (out of its lighting range), glowstone will actually cast a shadow, despite it being a light-emitting block.

Bugs

 * Glowstone can no longer be powered by redstone due to it being a "glass" block as of 1.0.
 * However this was changed in snapshot 12w06a to allow it, but it has caused other interesting things.
 * Altering Glowstone or rails on Glowstone (From 1.8 and before) appears to cause the game to crash. This seems to occur when the rails extend to outside of the render distance.
 * Nether Wart cannot be planted under natural terrain generated glowstone veins regardless of height and obstructions.