The primary purpose of this study was to obtain some knowledge of the heavy-mineral assemblage in the Jacksonian sediments of Mississippi and adjacent parts of East Texas, Louisiana, and western Alabama. Sixteen non-opaque heavy minerals were found and identified. Two sedimentary provinces are distinguished: the province of Mississippi and western Alabama to the east is characterized by the abundance of kyanite, staurolite, and the presence of epidote; the province of East Texas to the west is characterized by the abundance of zircon, titanite, and magnetite. Epidote is present in the Texas province but rather rare. Magnetite is rare in the eastern province, whereas ilmenite is abundant. The differences in the heavy-mineral assemblage, between stratigraphic units of the Jacksonian sediments, are not conspicuous. The feasibility of using the heavy-mineral assemblage as a marker for the differentiation of stratigraphic traits within the Jacksonian sediments is discussed.