Bulletin 18 Abstract: Undisturbed Paleozoic sediments form the bedrock surface of Indiana. The most common minerals in these sediments are calcite, clay minerals, dolomite, glauconite, goethite, gypsum, hematite, limonite (hydrous iron oxides), quartz, and siderite. Found less abundantly are anhydrite, apatite, aragonite, barite, celestite, copiapite, epsomite, fluorite, marcasite, melanterite, millerite, pyrite, pyrrhotite, smythite, sphalerite, strontianite, sulfur, and wad. These minerals occur in veins and cavities; along bedding, joint, and fracture surfaces and stylolite seams; and in geodes in limestones. Reported and observed locations and modes of occurrence are presented for each of the minerals except most clay and minerals. The more unusual minerals that occur in glacial materials of Indiana, native copper, diamond, galena, native gold, and native silver, are described in full. A literature study was the basis for a brief discussion of the history of Indiana minerals. The present report questions the reported occurrences in Indiana of native bismuth, graphite, malachite, moissanite, nitromagnesite, and stibnite.