Technical blocks

Technical blocks are blocks that cannot be acquired legitimately and serve various purposes during events within the game.

Piston related technical blocks
These blocks serve a purpose when a piston is used.

Piston Extension
Block 34 is a block used by the piston's extension arm. One of the data bits of this block defines if it is a normal piston or a sticky piston extension.

Block 36
Block 36 is a block used by pistons. It is a side effect of the method of storing moving blocks as tile entities instead of entities. This block's color, when located next to a block in the world, is black. When a block next to it is removed, it becomes invisible, can be walked through, and when light passes through it the light level decreases by 1. They are unbreakable by traditional methods; however, can be removed by right-clicking. The game treats the block as stone when it comes to breaking animation and step sound. In the inventory it has a top of grass block texture in terrain.png, presumably since it is the first texture, and it cannot be placed.

Burning Furnace
This is a block used to make furnaces shed light when smelting. It has a different texture than the normal furnace and emits particles.

Glowing Redstone Ore
This is a block used to make Redstone Ore glow when stepped on, right-clicked, or left-clicked.

Off-state Redstone Torch
This is like a Redstone Torch, but it's off when placed. Destroying this will give an On-state Redstone Torch. If placed, will turn on when an adjacent block changes.

Active Redstone Repeater
This is the on state of the Redstone Repeater.

Flowing Water
The flowing water block tells the game to check for any air blocks around it and put some water into them if applicable.

Flowing Lava
The flowing lava block tells the game to check for any air blocks around it and put some lava into them if applicable.