Sampleite
Sampleite has a general formula of NaCaCu5(PO4)4Cl•5(H2O). It was first described in 1942 for an occurrence in Chuquicamata, Chile and was named after Mat Sample, a mine superintendent for the Chile Exploration Company.
Sampleite is orthorhombic, which means crystallographically, it contains 3 unequal axes with angles that are 90°. It belongs to the space group 2/m. In a thin section it has a high surface relief and will have sharp boundaries with the surrounding medium. Sampleite is anisotropic and has visible pleochroism and birefringence.