This is a Crystalized Azurite from Milpillas Mine from, Sonra, Mexico. A part of the Santa Cruz Municipal. Azurite is a copper based mineral that usually forms botryoidally. It is rare for it to form in a crystal structure like the one here.
This piece measures approximately 4.5 cm x 3cm x 1.8cm. It comes with the acrylic base it is on which measures 5cm x 5cm.