The identification of volcanic ash as a temper used in pre-Hispanic ceramics in northern Yucatan is questioned. Earlier authors who raised the question of an origin for volcanic ash in Yucatan are cited. The possible indigenous materials that could have been identified as volcanic ash have been examined and the conclusion reached that the material in question is the mineral palygorskite. It is recommended that unless ceramicware from Yucatan is found that actually contains true volcanic detritus (glass shards, grains of feldspar, amphibole, pyroxene, rutile, zircon, and so forth), reference to ash temper be avoided. -- AATA