1.   The movement of the calcium crystals sends a signal to the brain to tell us the direction of gravity.

2.   During space flight, the loss of bone elevates calcium levels in the body, potentially causing kidney stones and calcium crystals to form in other tissues.

3.   At left are pre-Columbian skulls stippled with calcium crystals.

4.   This destroys the calcium oxalate crystals in the leaves.

5.   Doctors also found what appeared to be calcium oxalate crystals, but needed further tests to confirm it.

6.   It contains microscopic needle shaped formations of calcium oxalate crystals and can make the plan very unpalatable without long cooking.

7.   It contains microscopic, needle-shaped formations of calcium oxalate crystals and can make the plan very unpalatable without long cooking.