ABSTRACT Embedment of sintered bauxite into Berea, sandstone core, and shale core at closure pressures up to 10,000 psi (69 MPa) is reported. Several variables influencing fracture closure are examined: closure pressure, proppant size and size distribution, proppant concentration (up to a monolayer), formation hardness and surface roughness. Comparison is made with sand proppant. Empirical equations are derived to describe embedment into sandstones and shale for non-crushing proppants such as sintered bauxite.