A crystal ball. This polished ball is fashioned from quartz (variety rock crystal) and does show some double refraction, but not as conspicuous as would be observed in a calcite ball.

Size: 4300px × 4300px
Location:
Photo credit: © World History Archive / Alamy / Afripics
License: Licensed
Model Released: No

Keywords: archival, archive, ball, ball., calcite, conspicuous, crystal, double, fashioned, geology, historical, history, observed, polished, quartz, refraction, rock, show