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Calcite. From wp-en. Banded agate. The specimen is one inch (2.5 cm) wide.
Picture made without a camera by laying the carving on a flat bed scanner.
Released to the public domain by Adrian Pingstone in May 2003. by en:User:Arpingstone
Public domainPublic domainfalsefalse
This work has been released into the public domain by its author, Arpingstone at English Wikipedia. This applies worldwide. In some countries this may not be legally possible; if so: Arpingstone grants anyone the right to use this work for any purpose, without any conditions, unless such conditions are required by law.Public domainPublic domainfalsefalse
The picture shows the double refraction of the light by the calcite.