Packed Ice

Packed Ice is a unique type of block, as it is only found in the rare Ice Plains Spikes Biome.

Compare & Contrast
As the name suggests, Packed Ice is a variation of the commonly found Ice Block. Packed Ice is hardly transparent, it does not melt and allows for Mob Spawning, unlike Ice. But both blocks still retain their sliding effect. Both are non-renewable. Packed Ice will not create a Water Source blocked when mined, unalike Ice.