Rare crystals are approximately cubic, dodecahedral, or octahedral. Crystal forms (cubic, octahedral, dodecahedral). This pattern also approaches the rhombic dodecahedral honeycomb or trapezo-rhombic dodecahedral honeycomb. Some minerals such as garnet form a rhombic dodecahedral crystal habit. It may also occur as cubic, octahedral, or dodecahedral crystals. The "vertex-first" parallel projection of the 24-cell into 3-dimensional space has a rhombic dodecahedral envelope. It is the net of a rhombic dodecahedral pyramid. It is the only dodecahedral stellation with this property, apart from the dodecahedron itself. Sphalerite crystallizes in the isometric crystal system and possesses perfect dodecahedral cleavage. Various solid hydrates are known with 8-coordination in square antiprism and dodecahedral geometry. The smallest possible fullerene is the dodecahedral . Close packing of spheres generates a dodecahedral tessellation with pentaprismic faces. It is used in the cell-transitive hyperbolic space-filling tessellation, the bitruncated order-5 dodecahedral honeycomb. Some quasicrystals have dodecahedral shape (see figure).