Ask the Carey Brothers: Synthetic marble?

Q. My husband and I are considering replacing the vanity tops in our two bathrooms. We have heard a lot about “synthetic marble” and “synthetic onyx.” Can you tell me what these products are and the differences between the two?

A. The products to which you refer are called cultured marble and cultured onyx. These happen to be two of the most popular finishes for bathroom vanity tops. Although the products are very similar in construction and equally durable, there are distinct differences in appearance.

Cultured marble is a material composed of a mixture of natural stone and polyester resin. It has a gel-coat finish, which provides a nonporous, stain-resistant surface. No two pieces are ever the same. Cultured marble products have a deeply veined colorization throughout the substance, not merely on the exterior, which results in the appearance of real marble.

Cultured onyx also is made of natural stone and polyester resin with a gel-coat finish. However, onyx products have a radiant translucence, giving it depth, which is produced by superior materials.