Through making a series of experiments on the etching of three different samples of tourmaline
we have probed the best etching conditions of this mineral. It is shown that when the sample is etched either with 40% HF at 35℃ for 30 min or with KOH at 40℃ for 20 min
fission tracks can be obviously seen on the plane of the mineral which is parallel to the c axis under optical microscope.