AbstractPhytoliths are an important component for interpreting the ancient botanical record. However, phytoliths can be altered through heating, either as the result of such activities as firing ceramics, clay molds use for casting metal or in hearths. Phytoliths can also be altered through heating as the result of creating comparative sample from living plants. By heating phytoliths at graduated intervals it was found that different types of phytoliths lost their diagnostic morphological characteristics at significantly different temperatures. The phytoliths used in this study are derived from economically important plants to Chinese archaeology and culture. Given the consistent results of the alteration of different type of phytoliths at specific temperatures it should eventually be possible to use phytolith alterations as a proxy measure of the original firing temperature of ancient objects and features. Microsc. Res. Tech. 2012. © 2012 Wiley Periodicals, Inc.