Monzonite
Photographed by Michael P. Klimetz
[var. Larvikite]
Oslo Graben
Larvik
NORWAY
Monzonite is an intermediate igneous intrusive rock composed of approximately equal amounts of sodic to intermediate plagioclase and orthoclase feldspars with minor amounts of hornblende, biotite and other minerals. Quartz a minor constituent or is absent, although with greater than 10% quartz the rock is termed a quartz monzonite. If the rock has more orthoclase or potassium feldspar it grades into a syenite. With an increase of calcic plagioclase and mafic minerals the rock type becomes a diorite. The volcanic equivalent is a latite. The monzonite of Plauen near Dresden in Saxony, Germany frequently possesses dark-red microcrystalline laths of Grotite, a form of Titanite. Plauen is the type-location of Grotite.
Photographed by Michael P. Klimetz
Plauen bei Dresden
Saxony
GERMANY
Photographed by Michael P. Klimetz
Plauen bei Dresden
Saxony
GERMANY
Photographed by Michael P. Klimetz
Plauen bei Dresden
Saxony
GERMANY
