KOMUNIKATY NAUKOWE Wstępne dane o spinelu właściwym (MgAl2O4) z kopalni granodiorytu Łażany II w masywie Strzegom–Sobótka

Abstract

Preliminary data on spinel (MgAl2O4) from the Łażany II granodiorite quarry of the Strzegom–Sobótka massif. A b s t r a c t. The study conducted in the granodiorite quarry at Łażany (Strzegom–Sobótka granitoid massif, Sudetes, Poland) identified spinel crystals within a marble interlayer contained in hornfels. Spinel occurs in the form of perfect octahedrons of violet color. The crystals reach a size of up to 2 mm, but typically are much smaller. The hornfels zone with a calc-silicate rock and a marble inlayer is about a dozen meters thick and most probably comes from the metamorphic cover of the Strzegom batholith. Semi-quantitative analyses of spinel were performed. In addition, chondrodite-like or monticellite-like minerals and vesuvianite have been found together with the spinel.