Note on the occurrence of anatase in some fireclay deposits

In X-ray studies of fireclays we have frequently observed the presence of anatase to the extent of 1 or 2% with little or no rutile, and no brookite. Chemical analyses of these clays usually record 1–2% of TiO 2 and occasionally more (Ennos and Scott, 1924). The mineralogical form of the TiO 2 is usually not stated, but a number of references to the observance of rutile needles give the impression that rutile is the form in which titania occurs in these deposits. Our own observations based on X-ray powder photographs lead us to conclude that anatase is commonly present and that rutile is either absent or present in smaller quantities. We have not detected brookite.