Picking through rice was the first duty in our household. First thing in the morning after everyone was washed and the kids packed off to school the ladies of the house would sit in the cool morning sunlight and pick stones and other undesirable foreign matter out of the rice. Failure to do so could mean broken teeth and would leave you unable to enjoy your meal for fear of injury.
This job was compulsory; some say the white rocks were added to the rice on purpose to increase the weight of the sack. While this was true in some cases the contamination was mostly due to the primitive husking methods. In those days the rice was usually threshed on the side of the road and then pounded in large mortars with pestles to loosen the husks. I will always remember the rhythmic thud of the rice husking as three or four sets of people got going and it started to sound like music.