Sand Blocks

Sand Blocks are special Environmental Blocks that conform to gravity. They deal damage to any player or mob it falls on.

Location
Sand is usually found in very vast amounts: Usually found in the form of a Desert, large areas of underground sand can be found as well. Digging through sandy areas is tedious and potentially dangerous.

Harvest
Because of its mechanics, and the fact that it is usually found in mass, Sand is especially easy to harvest: Simply Picking the bottom block will cause entire sections of Sand Blocks to collapse, and the sand block above it will fall into the location you're already digging. However, because this also duped the sand, it was removed.

Usage
The Sand Block's easy harvestability make it a prime candidate for an easy Coin making technique.

Because of its unique gravity conforming mechanics, Sand Blocks can be used to create Traps, both against Monsters or Players: Sand Blocks can be placed over a Cobweb. When the cobweb is destroyed, it releases the Sand Blocks. This can have many useful and fun effects, like crushing traps, or pitfalls. The same effect can be done with other environmental objects, like the top of trees, or items like torches.

Sand is also useful in the creation of mining shafts. While digging downward is can be used to create walls in caverns without ever actually entering the cavern.

Sand is effective at drying out oceans and waterpockets underground.

Proboably most important is that sand can be used as ammunition for the Sandgun.