Calcite
CaCO3
hexagonal - scalenohedral, -3 2/m
Distorted scalenohedrons
{21-31}. Contact twins on {01-12}, elongated in the direction of one scalenohedron
edge.
Guanajuato, Mexico.
Width of the twins: 1-1.5
cm. Inv.No. 56/1666.
Calcite
crystal drawings:
left: scalenohedron {21-31}
middle: the same, as contact
twin on {01-12}
right: the same as in the
middle, but some scalenohedral faces are suppressed, the shape is elongated
parallel to one of the edges