I have encountered some difficulties with the fossils of conodont. Recently, we have obtained some conodont from the Triassic. However, many of the conodont have some impurities on their surfaces (calcite, hard soil, quartz particles?). This may affect the identification work. We attempted to solve it with acetic acid, but the effect was not perfect (some fossils were broken). How should we deal with it? Do you have any better solutions?