1.8" Black Tourmaline (Schorl) and Orthoclase Feldspar - Namibia

Here is a beautiful association of black tourmaline (schorl) and white orthoclase feldspar, collected from the Erongo Mountains in Namibia. The schorl features excellent vitreous luster.

Schorl, also known as "black tourmaline" or "black schorl", is a black form of tourmaline that often occurs as lustrous prismatic crystals. The crystals can be stubby or elongated and typically feature striations that run along the length of the crystal. Many schorl crystals have flattened pyramidal terminations. They can also form in radiating, columnar and stalactitic aggregations, as well as small needle-like inclusions within quartz (tourmalinated quartz) and in massive form.

Schorl is a basic sodium iron aluminum boro-silicate and the generic chemical formula is NaFe2 + 3Al6(BO3)3Si6O18(OH)4 . It has been used for everything from jewelry to piezoelectric guitar pickups.

Orthoclase is a feldspar mineral with the chemical formula KAlSi₃O₈ and has a hardness of 6 - 6.5 on the Mohs hardness scale. It is considered a key component in many igneous rock formations and is one of the more abundant minerals throughout the continental crust. It can form individual crystals, however it's most commonly known for its pink coloration within granite rock. It has many commercial uses, including application in the production of a wide variety of ceramics and is sometimes used in the manufacturing of glass.

Tourmaline var. Schorl & Orthoclase
Erongo Mountains, Namibia
1.8" wide