Pyrite FeS₂
Equant Habit
Pyrite crystals with equal width, height and length in a cubic, octahedral and dodecahedral shape
Cube: 3 cm

Pyrite Penetration Twin
Navajun, Spain
Size: 4.2x3.7x3.3cm, 2.6x2.4x2.3cm

Two crystals of the same mineral crystallize together in such a way that they are joined at a common symmetry or crystallographic plane forming a twinned crystal. When two parts of the twinned crystals grow into each other, they are called penetration twin.

Galena PbS
Equant, blocky Habit
Assemblage of galena crystals in their cubic shape
Size: 20 cm






Flourite CaF₂
Equant Habit
Flourite crystals with equal width, height and length in a cubic and octahedral shape
Top: 8cm
Bottom: 3cm each





Quartz SiO₂
Prismatic Habit
One of the most common of crystal Habits being “pencil-like", elongated along one axis
Size: 10 cm





Carborundum SiC
Tabular Habit
Broad, flat or book-like crystals
Size: 15 cm





Calcite - Iceland spar CaCO₃
Rhombohedral Habit
Bent cubes in which each face of the crystal is a rhombus with no right angles
Size: 5 cm each