rapakiwi

from The Century Dictionary.

• noun In petrography, a variety of porphyritic granite, composed of flesh-colored orthoclase, with some oligoclase, smoky quartz, and a little biotite and hornblende. It has large phenocrysts of feldspar, often with circular zones of inclusions. It is used for monumental and building purposes in northern Russia, but falls to pieces upon weathering, hence the Finnish name.