A resonance-ultrasound microscopy has been developed for mapping a material's elastic constant in a localized surface region. It detects the effective elastic modulus through a resonance frequency of free vibrations of a solid probe touching the specimen via a small tungsten-carbide bearing. Langasite (La 3 Ga 5 SiO 14 ) crystal is used as a probe because of the low sensitivity of its elastic constants to temperature and its high piezoelectric coefficients. The vibration of the probe is excited

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... and detected with a surrounding solenoid coil. This noncontacting acoustic coupling isolates the probe vibration and measures the resonance frequency with an accuracy better than one part in 10 5 . This microscopic method is applied to a composite material consisting of silicon-carbide ͑SiC͒ fibers in titanium-alloy matrix. The stiffness distribution inside a single fiber was determined.