Mindat Logo

Quartz (Var: Chalcedony)

Quartz (Var: Chalcedony) : SiO2
minID: KKC-EM8

Photo Copyright © Amir C. Akhavan  - This image is copyrighted. Unauthorized reproduction prohibited.

A small piece of silicified limestone with secondary fillings of blueish chalcedony in the voids in between. The blueish chalcedony (see second photo shot in incandescent light) shows a rather strong fluorescence of green color in short-wave UV light. Some of the chalcedony shows a botryoidal habit and can also be overgrown by small quartz crystals. In these cases the fluorescence shows a banding that coincides with the agatoid banding seen in the wall-lining chalcedony. The creme-colored parts are completely silicified (no calcite is left in the matrix), resemble porcelain in places and are almost opaque. They show a white and blueish white fluorescence. Pure blue patches are reflections of the UV lamp.
Width of the specimen: 7cm.
UV photo white balanced to 5000K.
Found in April 2010 in the rubble at the road cut shown in the locality photos. Collection Alfredo Petrov.

This Photo was Mindat.org Photo of the Day - 26th Oct 2011

This photo has been shown 2954 times

Photo added: 27th Apr 2010

Other Views - click to switch

View User Page & Photos View Chalcedony Gallery Create Talk Page Light Background

Mineral and/or Locality  
Search Google  
Copyright © Jolyon Ralph and Ida Chau 1993-2014. Site Map. Locality, mineral & photograph data are the copyright of the individuals who submitted them. Site hosted & developed by Jolyon Ralph. Mindat.org is an online information resource dedicated to providing free mineralogical information to all. Mindat relies on the contributions of thousands of members and supporters. Mindat does not offer minerals for sale. If you would like to add information to improve the quality of our database, then click here to register.
Current server date and time: December 19, 2014 07:16:13
Mineral and Locality Search
and/or Locality:
Fade toolbar when not in focusFix toolbar to bottom of page
Hide Social Media Links
Slideshow frame delay seconds