Isometric System
The Cubic crystal system which consists of three axes, each of equal length and perpendicular to others.
Isometric System
Hexagonal System
Tetragonal System
Rhombohedric (Trigonal) System
Orthorhombic System
Monoclinic System
Triclinic System
The above seven crystal systems are listed in order of their decreasing symmetry.
Isometric system
The isometric is one of 7 (6 in newer texts) crystal systems used to categorize minerals. It is composed of three axes of equal length that intersect each other at 90° angles. It is commonly called the cubic system.
The cubic crystals (ISOMETRIC SYSTEM) are silver white. Luster metallic, streak grayish black. It occurs with other cobalt and nickel minerals and, more commonly, in contact metamorphic zones.
Colemanite ... hydrated calcium borate ...
Minerals shaped as tetrahedrons belong to the isometric system.
2. The building block of all silicates. It is composed of one silicon atom equidimensionally placed around four oxygen atoms.
For example, all crystals of the isometric system possess four 3-fold axes of symmetry which proceed diagonally from corner to corner through the center of the cubic unit cell.
This occurs in gems forming in all the crystals system except the cubic or isometric system.
Dull - surface luster that does not efficiently reflect back light.
Spinel crystallizes in the isometric system; common crystal forms are octahedrons, usually twinned. It has an imperfect octahedral cleavage and a conchoidal fracture. Its hardness is 8, its specific gravity is 3.5-4.
Crystal forms in the isometric system have the highest degree of SYMMETRY, when compared to all the other crystal systems. Did you know that there is only ONE object in the geometrical universe with perfect symmetry? Considerthe sphere (fig. 3.1).
Octahedron - An eight-sided crystal of the Isometric System (Diamond, Pyrite)
Oolitic - Habit made up of small rounded grains (oolites)
Opalescence, Opalescent - Showing an internal play of colors or iridescence. (Opal) ...
(a) A diamond is a natural mineral consisting essentially of pure carbon crystallized in the isometric system. It is found in many colors. Its hardness is 10; its specific gravity is approximately 3.52; and it has a refractive index of 2.42.
The seven unique crystal systems, listed in order of decreasing symmetry, are: 1. Isometric System, 2. Hexagonal System, 3. Tetragonal System, 4. Rhombohedric (Trigonal) System, 5. Orthorhombic System, 6. Monoclinic System, 7. Triclinic System.
Diamond crystallizes in the Isometric system and graphite crystallizes in the hexagonal system. Somewhat of a surprise is that at surface temperatures and pressures, Graphite is the stable form of carbon.
 See also: Crystal, Mineral, Shape, Length, Minerals
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