O55 Chalcedony & Calcite

O55 chalcedony & calcite from Crawford, Nebraska 

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