O53 Chalcedony & Calcite

O53 chalcedony & calcite from Crawford, Nebraska 

lime green chalcedony & red calcite known as watermelon rock due to its food appeal. 
6.3 ounces weight 3”x2 1/2” size responds best under midwave and shortwave. Whitish yellow response under longwave.  The purple response is an unknown mineral response.