Orthoclase (Kspar)KAlSi3O8
Class: Silicate Subclass: Framework Hardness: 6 - 6.5 Density: 2.6 Streak: White Lustre: Vitreous Habit: Polysynthetic twinning Colours: Pinky-white | | Crystal System: Orthorhombic Cleavage: Perfect Fracture: Subconchoidal Magnetism: None Reaction with HCl: None | Identification in hand sample: Colour and evidence of exsolution with plagioclase. Associations: Very common in granite, granodiorite, syenite and related felsic rocks. Comments: Orthoclase is the potassic variety of feldspar. |