This cube of metamorphic rock reminds me of a picture of stars and galaxies against the deep blackness of space.  The rock is likely from a listwanite as seen by the green spots and the mixture of brown and white minerals.

Rock type: Likely a listwanite.

Breccia is a type of clastic rock made up of particles trapped in a matrix.  The particles in breccias are angular and result from rocks and rock fragments that get trapped in a matrix after a landslide or cave collapse.  The angular shapes suggest that the rocks and rock fragments were trapped before they could be worn down and rounded.

Chemical composition: Listwanites are formed from ultramafic rocks that are partially altered to carbonate minerals.  The main minerals found in listwanites are quartz, serpentines, and carbonates.