Trancas Geode Heart from Mexico. Trancas consists of Quartz, Chalcedony & Agate. This Trancas geode heart has a beautiful mainly white appearance and a lovely little rainbow in a calcite patch. This heart measures roughly 3.9cm High, 4.6cm wide & 1.2cm deep. Trancas Geodes also Fluoresce under short wave UV light.