Quartz

Quartz is a tile-matching puzzle game on a diamond-shaped playing field. The object of each level of the game is to clear the screen from the blocks by grouping them. Groups of four or more blocks of the same color disappear from the field.

New tiles appear at the top of the field and can be dropped next to any other tile or on top of it. If there's a space under a tile, it will slide down there due to gravity until it can't slide anymore.

In addition to the normal colored blocks, there are two types of special blocks: nuclear blocks that explode when next to a same-colored group, and black blocks that can't be removed directly. Also there's a bar in the bottom-left corner of the screen that builds up each time the player drops a block on the field without making a group. When this bar is full, the game drops several of black blocks on top of the existing blocks.