Corsi Collection of Decorative Stones

view of stone 984

Corsi 984, approx. 145 x 73 x 40 mm, © Oxford University Museum of Natural History

OUMNH Number: 984  
Name and quarry location: Porfido delle Alpi, from the Alps  
Geological description: Quartz porphyry. Greyish brown colour. Prominent white subhedral feldspar phenocrysts, some showing compositional zoning with lamellar-twinned interiors and untwined rims. Rounded glassy quartz phenocrysts and prismatic dark brown ferromagnesian mineral, probably amphibole. All set in very fine-grained pale brown groundmass. Similar in mineralogy to 0983, but with different proportions of feldspar and quartz phenocrysts.  
Comments: This locality has not been confirmed.  
References:  
Further information:
 


Corsi's classification: Class 15. Porphyry; Species 1.; ii. Italian porphyries  
Corsi's text: 196.10/ S26.2 Altro dello stesso luogo [Porfido delle Alpi]  

Full entry in English

Enter some search terms
Show results as:

search tips

Searches the database for all stone records containing the words you enter. To search for a text string, put it between quotation marks. To search for stone records that don't contain a word, put a minus sign in front of it.

For example, entering: granite "coarse-grained" -Egypt will find all the coarse-grained granites that do not come from Egypt.

Terms of three characters or less have not been indexed.