Learn how to say Quartz correctly in English with this tutorial pronunciation video.
Oxford dictionary definition of the word quartz:
a hard mineral consisting of silica, found widely in igneous and metamorphic rocks and typically occurring as colourless or white hexagonal prisms. It is often coloured by impurities (as in amethyst, citrine, and cairngorm).
mid 18th century: from German Quarz, from Polish dialect kwardy, corresponding to Czech tvrdý ‘hard’