a) chrome alum octahedra embedded in alum
cube (left) and alum octahedron,
b) seignette salt and potassium dihydrogen
phosphate (front),
c) Mn-doped seignette salt (left), copper
calcium acetate*6H2O and
rocksalt*2glucose*H2O (right),
d) triglycine sulfate,
e) sodium chlorate (left) and sodium bromate,
f) nickel ammonium sulfate*6H2O (top) and
lithium sodium chromate*6H2O,
g) + h) opals, diameters about 2 cm.
The coin has a diameter of 1.9 cm.
Crystals shown in fig.s a)-f) are permanently
exhibited in the entrance area of the
Crystallography department,
Albert-Ludwigs-Universität Freiburg, Germany.