Rare-earth disilicates (RE2Si2O7) are investigated for use as oxidation-resistant alternatives to carbon or BN fiber-matrix interphases in ceramic matrix composites (CMC). Dense , , -Y2Si2O7, and -Ho2Si2O7 pellets were formed at 64MPa and 1050 degrees C-1200 degrees C for 1h using the field-assisted sintering technique (FAST). Pellet modulus was measured using nanoindentation, and Vickers hardness was measured at loads of 100, 500, and 1000g. The sliding stress of SCS-0 SiC fibers incorporated in -, -, and -RE2Si2O7 matrices were measured by fiber push-out. Deformation of RE2Si2O7 after indentation and after fiber push-out was characterized by TEM. Implications of the results for use of RE2Si2O7 as a fiber-matrix interphase in CMCs are discussed.