Kaszab Zoltán (szerk.): A Magyar Természettudományi Múzeum évkönyve 72. (Budapest 1980)

Örkényi-Bondor, L.: Andesite agglomerate from Zebegény village, Börzsöny Mountains (Hungary)

Fig. 1. Plagioclase intergrowth according to Börzsöny law. Lower nicol only, x 80. Fig. 2. Plagioclase intergrowth according to Börzsöny law. Crossed niçois, x 80. Fig. 3. Plagioclase twinning after breaking. Lower nicol only, x 80. Fig. 4. Plagioclase twinning after breaking. Crossed niçois, x 80.