Derek Anderson, age 11, of St. Catharines, Ontario, Canada, for his question:

Are the colors of alabaster real or artificial?

Natural alabaster comes in lily white and several gentle pastel shades. It is much paler than those pretty little carvings that capture the colors of vivid violets and bold forest leaves. .In most cases these charming art objects have been tinted with various dyes. This is not hard to do because alabaster is a soft, rather porous mineral.

Alabaster may be one of two marble type minerals, but neither of these natural stones comes in very brilliant colors. The alabaster of ancient times usually was a form of calcium carbonate, the same chemical from which marble is made. As a rule, the alabaster of modern times is a compacted form of the mineral gypsum, which is calcium sulfate.

Both alabasters are milky white stones, usually tinted with streaks or blotches of pearly grays or yellowish browns or pale petal pinks. In most cases, these soft colors were added by traces of iron that got mixed with the original ingredients. Alabasters are lightweight stones, so soft that you can scratch them with your fingernail.

All alabaster is made from impacted minerals mixed with a high percentage of water. When the pure white mineral is dumped into boiling water, it loses its clear translucence and becomes opaque. It is thought that this happens because the mineral loses water and becomes dehydrated. And, since the water can be removed, it also can be replaced. When alabaster is soaked in certain dyes, the liquid seeps through its pores and changes the natural colors to artificial colors.

Natural alabaster is a very beautiful stone, especially when its surface is polished to a waxy luster. Some people think that changing its gentle colors is rather like gilding the lily. What's more, the artificial dyes may eventually fade and when the stone is washed, they may dissolve and disappear with the drain water.

However, those art objects of tinted alabaster are very pretty and it's nice to own one. They are extra lovely for two reasons. Alabaster is somewhat translucent, which enables you to see below the smooth shiny surface. And the colors appear in patches of deeper and paler tones.

Dyed alabaster may look like a mass of pink and red rose petals, yellow or orange primroses, blue and purple pansies or pale buds mixed with dark green leaves. Just remember that your alabaster is a fragile stone, easily scratched or shattered.

The old style calcite alabaster was formed with deposits of marble and limestone. The basic ingredients in all these minerals came from shells of tiny sea creatures that lived in the ancient seas. Gypsum alabaster also is a gift from the sea. It was deposited in places where the water evaporated, leaving its dissolved chemicals high and dry.