Diamond cubic strong isotropic property. Namely, for any two vertices "x" and "y" of the crystal net, and for any ordering of the edges adjacent to "x" and any ordering of the edges adjacent to "y", there is a net-preserving congruence taking "x" to "y" and each "x"-edge to the similarly ordered "y"-edge. Another (hypothetical) crystal with this property is the Laves graph (also called the K crystal, (10,3)-a, or the diamond twin). The compressive strength and hardness of diamond and various other materials, such as boron nitride, is attributed to the diamond cubic structure. Similarly truss systems that follow the diamond
Arizona Mining and Mineral Museum Parts of the collection were expected to be included in the planned centennial museum, which was to be called the Arizona Experience Museum. The mineral collection features displays of minerals from well-known Arizona mineral localities and specimens from Arizona copper mines, including a piece of native copper that is in its longest dimension. Displays on the lapidary arts feature faceted gemstones and cabochons made from Arizona minerals. Mineralogical principles are illustrated by displays on mineral crystal systems, crystal habits, fluorescent minerals, and causes of color. Unusual items in the mineral collection include a piece of the Meteor Crater meteorite, fulgurites,