Olgite is a rare blue-green colored

phosphate mineral Phosphate minerals contain the tetrahedrally coordinated phosphate (PO43−) anion along sometimes with arsenate (AsO43−) and vanadate (VO43−) substitutions, and chloride (Cl−), fluoride (F−), and hydroxide (OH−) anions that also fit ...

series that forms microscopic prismatic crystals that are

trigonal In crystallography, the hexagonal crystal family is one of the six crystal families, which includes two crystal systems (hexagonal and trigonal) and two lattice systems (hexagonal and rhombohedral). While commonly confused, the trigonal crystal ...

in structure. Its

chemical formula In chemistry, a chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbol ...

is . Olgite was discredited as a mineral name in 2008 by the International Mineralogical Association and is now the series name for bario-olgite and strontio-olgite (hypothetical mineral).Olgite on Webmin
/ref> The substance was named after Russian mineralogist Olga Anisimovne-Vorobiova (1902–1974).

References

Phosphate minerals Trigonal minerals Minerals in space group 164 {{phosphate-mineral-stub