Quartz is a hard mineral, a kind of stone. The sense here is the one inside electronic watches and clocks.

Quartzquartz(石英) is a hard mineral, a kind of stone是一種堅硬的礦物，是一種石頭. The sense here這裡講的意思 is the one inside electronic watches and clocks是電子錶和時鐘裡面那種

A tiny piece of quartz can be cut so that, when a little electricity runs through it, it shakes at a very steady speed. The watch counts those shakes, and that is how a quartz watch keeps time so well — even a cheap one. Shop signs still say “quartz” for that reason: the crystal is doing the timing, not a spring.

A tiny piece of quartz一小片quartz can be cut so that可以被切割成, when a little electricity runs through it只要通過一點點電流, it shakes at a very steady speed就會以非常穩定的速度震動. The watch counts those shakes手錶會計算這些震動次數, and that is how a quartz watch keeps time so well這就是quartz手錶(石英錶)走得這麼準的原因 — even a cheap one就算是便宜的也一樣. Shop signs still say “quartz” for that reason商店招牌因此還是會寫「quartz」: the crystal is doing the timing, not a spring是這顆晶體在計時，不是靠發條

Though actually, quartz is also one of the most common minerals on Earth. A lot of sand is quartz, and it turns up in granite and in glass.

Though actually不過其實, quartz is also one of the most common minerals on Earthquartz也是地球上最常見的礦物之一. A lot of sand is quartz很多sand(沙子)其實就是quartz, and it turns up in granite and in glass也出現在花崗岩和玻璃裡

When a learner’s dictionary points at watches and clocks, they mean that small, steady crystal inside. The word is ordinary in shops and in science class; it does not feel fancy.

When a learner’s dictionary points at watches and clocks當學習型字典指向手錶和時鐘的意思時, they mean that small, steady crystal inside指的就是裡面那顆穩定震動的小晶體. The word is ordinary in shops and in science class這個字在店裡和自然課裡都很平常; it does not feel fancy一點也不講究、不特別