.72" Schorl, Feldspar & Smoky Quartz - Namibia

Here we have a lustrous group of tiny schorl crystals sitting atop a nicely terminated chunk of feldspar. The largest schorl is double-terminated. The specimen appears to have possibly broken off from a larger piece of smoky quartz.

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.
Feldspars are a group of rock-forming tectosilicate minerals. It is also one of the most common minerals on earth, making up nearly 60% of the crust.
Smoky quartz is a grey-brown to black variety of quartz. This common name is derived from from the appearance of smoke within the quartz crystal. Dependent on the location and the chemicals present during formation, smoky quartz can appear opaque black, however it’s typically translucent to some extent. It’s believed that the quartz gains this color from a combination of natural irradiation and aluminum impurities.
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DETAILS
SPECIES
Smoky Quartz, Schorl & Feldspar
LOCATION
Erongo Mountains, Namibia
SIZE
Largest Schorl is .72x.55: on 1.72x1.61" matrix
CATEGORY
ITEM
#31890