clock noun. jam kuarza.
quartz crystal (kwôrts krĭsʹtəl) noun. A small crystal of quartz accurately cut along certain axes so that it can be vibrated at a particular frequency, used for its piezoelectric properties to produce an electric signal of constant known frequency, hablur kuarza.
quartz (kwôrts) noun. A very hard mineral composed of silica, SiO2, found worldwide in many different types of rocks, including sandstone and granite. Varieties of quartz include agate, chalcedony, chert, flint, opal, and rock crystal, kuarza.
(kwôrtʹsīt´) noun. A rock formed from the metamorphism of quartz sandstone, kuarzit