Corsi Collection of Decorative Stones

view of stone 995

Corsi 995, approx. 145 x 73 x 40 mm, © Oxford University Museum of Natural History

OUMNH Number: 995  
Name and quarry location: Granito antico, locality unknown  
Geological description: Porphyrtic trachyte. Abundant feldspar phenocrysts up to 15mm showing complex twinning, concentric zoning of inclusions and a tendency to cluster. Sparse microphenocrysts of amphibole substantially altered to rusty brown mineral (also occurs in the white feldspars). Possible rare quartz phenocrysts. Groundmass of milky-white and pale grey feldspars showing tendency to fluidal structure round phenocrysts. Occasional angular (?cognate) xenoliths of fine-grained equigranular rock consisting of feldspar and altered amphibol;e.  
Comments: This has not been identified as coming from Egypt.  
References:  
Further information:
 


Corsi's classification: Class 16. Granites; i. Antique granite  
Corsi's text: 210.42/ S27.10 Altro [Granito antico]  

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