Minerals identify

Know how to recognize them

Lavendulan

Arsenate mineral

Lavendulan is an uncommon copper mineral, known for its characteristic intense electric blue colour. It belongs to the lavendulan group, which has four members: * Lavendulan NaCaCu5(AsO4)4Cl.5H2O * Lemanskiite NaCaCu5(AsO4)4Cl.5H2O * Sampleite NaCaCu5(PO4)4Cl.5H2O * Zdenekite NaPbCu5(AsO4)4Cl.5H2O

Lemanskiite and lavendulan are dimorphs; they have the same formula, but different structures. Lemanskiite is tetragonal, but lavendulan is monoclinic Lavendulan has the same structure as sampleite, and the two minerals form a series. analogue of zdenĕkite, and the arsenate analogue of sampleite.

Lavendulan was originally named for the lavender color of the "type" specimen, which has since been determined to be a mixture with no relationship to modern lavendulan. The mineral which is now called lavendulan is not a lavender blue color, and has no relationship to the “type” material from Annaberg. It often contains potassium as impurities.

Identification

Color of mineral

Blue
Green

The streak

Blue

Density ( specific gravity )

1.645

Luster ( interacts light )

Vitreous
Waxy

Crystal ( diaphaneity )

Monoclinic