As more exotic natural stones begin to gain in popularity for floors, walls, and countertop installations, many homeowners are beginning to give onyx a second look. This wild and translucent stone has some very unique characteristics that make it desirable in a number of situations.
Chemically speaking onyx is actually a type of marble, a metamorphic stone made up primarily of calcite. Therefore you may find some crossover in how the onyx is labeled, either as onyx or onyx marble, and in the case of some stones such as Alba Chiara, the onyx may be labeled simply as marble.
One of the things that make onyx so unique is the fact that it is completely translucent. If you hold a piece to the light, you can see shadows and shapes right through it. Therefore, onyx is often installed as counters and columns that can be backlit for a modern and dramatic presentation.
Even when it is being installed in non-lit area, the translucency of onyx needs to be considered. Because the stone is so fragile, it is often reinforced with a fiberglass backing that may be seen through the stone. Additionally, any color other than white mortar may show through the onyx, dulling its color. Ridges dragged through the mortar may also be seen through the onyx if they are not smoothed out as part of the installation process.
The other thing that makes onyx so unique and desirable is its incredibly wild color variation. Onyx can differ tremendously from piece to piece and even within one piece. Some onyx, such as Honey Onyx, merely displays its variation as different shades of the same color possibly mixed with white. Rainbow Onyx, or Red Multicolor Onyx, however may show several unusual colors within one piece. This can be challenging to blend during installation and a dry layout is recommended. Homeowners purchasing the stone should ask to see pictures of several pieces within one lot to get a good idea of the kind of variation they can expect so as not to be taken by surprise with the final installation.