Back to list

Orthoclase (Potassium Feldspar)

Orthoclase (Potassium Feldspar)

Main Deposits

Spain (notably Montigalà, Badalona), Madagascar, Italy, Russia

Back to list

Description and Characteristics

Orthoclase is one of the most abundant minerals in the Earth's crust, belonging to the feldspar group. Nevertheless, specimens from Montigalà - Batlloria (Badalona) hold significant regional interest. They appear as well-defined crystals within the granitic matrix of the Sierra de Marina, notable for their prismatic shapes and their white to pinkish coloration.
Chemical Formula $KAlSi_3O_8$
LusterVitreous; pearly on cleavage faces
StreakWhite
FractureConchoidal to uneven
CleavagePerfect in two directions at 90º
Hardness6 Mohs
Crystal SystemMonoclinic

Did you know...?

Its name derives from the Greek word orthos, meaning "straight," referring to its 90º cleavage angle.

In the Badalona area, these crystals are witnesses to the geological past of the Marina Massif, where the cooling of magma allowed for the formation of phenocrysts visible to the naked eye.

New-Age Properties

It is considered a stone of grounding and balance. It helps strengthen willpower and self-confidence, facilitating the release of emotional blocks and encouraging a positive attitude toward life changes.