Abstract
Conodont elements in limestone are generally collected from acid-insoluble residues by using heavy solutions (e.g., bromoform). To avoid the use of harmful heavy solutions, we have developed a new method of identifying conodont elements in limestone. Acid-insoluble residues were obtained by treating limestone samples with 10% acetic acid solution. The collected residues were then soaked in a 10% acetic acid solution containing 0.1 wt.% Alizarin Red S for 5 days. Apatite (conodont elements, pellet pieces, abiotic apatite minerals, etc.) in the residues was stained a color between orange and light red, enabling it to be easily distinguished from other minerals. This method enables conodont elements to be collected from limestone samples effectively and safely.