A pale blue massive dumortierite
occurs on a steep mountain west of Canta, 70 km NE of Lima. It has been used for cabochons since the end of the 1990s. It is usually fine-grained. Dumortierite can rarely form spheres up to 1 cm wide with a fibrous radial structure and a strong silky luster.
Ref: J.Hyrsl (2012) Gemstones of Peru, p. 49