Described by the Dutch lichenologist André Aptroot in 2002, Pyrenula quarztitica was first identified from specimens he collected five years prior from the Serra do Caraça in Minas Gerais, Brazil.

[2] The thallus of Pyrenula quartzitica is crustose, extending up to 10 cm in diameter, with a yellowish-brown colouration, and a somewhat glossy appearance without pseudocyphellae or a visible hypothallus.

The ascomal wall is substantial, lined with angular hyaline (translucent) crystals that react reddish with potassium hydroxide solution.

Ascospores are dark chocolate brown, arranged uniseriately within the ascus, ellipsoid with pointed ends, and show distoseptate division with enhanced pigmentation around the septa.

[2] Pyrenula quarzitica is endemic to the Serra do Caraça in Brazil, where it occupies both shaded and somewhat exposed quartzitic and sandstone substrates within forest remnants.