3d4 crystals

d4 crystal colors
1. A sickly, faded magenta
2. A soft, warm, pale green
3. Like frozen storm clouds
4. Pristine, pearlescent white

d4 crystal clump shapes
1. Tall and towering, like a city of monoliths
2. Growing like a gnarled tree
3. A stack of perfect cubes
4. A carpet of tiny, sharp spikes

d4 crystal properties
1. Glows in the presence of a troubled mind
2. Shattered by loud sounds
3. Multiplies with dangerous speed when exposed to light
4. Entrancing, hypnotic shapes and patterns

Special mention to Anonymous, for mentioning that perfectly cubic crystals were a tell-tale sign of crystal wombats.