This section is from the book "The Boy Mechanic Vol. 2 1000 Things for Boys to Do", by Popular Mechanics Co.. Also available from Amazon: The Boy Mechanic, Vol2: 1000 Things for Boys to Do.
A good way to clean pearl articles or ornaments is to moisten them with alcohol and then dry in magnesia powder or French chalk. These last two articles may be purchased at any drug store and the process of cleaning is absolutely harmless. It also polishes the pearl and will not bleach delicate colors.