Locality: Ahumada Mine, Chihuahua, Mexico
Size: 66 mm x 55 mm x 31 mm (2.6 in. x 2.2 in. x 1.2 in.)
Weight: 117 g (4.1 oz.)
Endlichite, also known as arsenatian vanadinite, is a variety of vanadinite in which arsenic has taken the place of vanadium. This specimen has elongated grayish brown crystals to 4 mm, some with flat and others with concave terminations. The difference in terminations is best seen with magnification.