A Guide to the Different Types of Natural Stone Sinks

It’s easy to fall in love with a beautiful natural stone sink, bathtub or countertop. But just like any other relationship, you want to know a little about the object of your affection before you make a lasting commitment.

Each of our sinks is carved from a single block of stone quarried from the slopes where rock has formed over eons. This means that each block has its own character, with infinite variations in its crystalline structure. Differences are evident in distinctive veining, mineral inclusions, minor pitting, or areas of deeper coloration. The color and characteristics of each stone block will vary from each other. These are the characteristics that create the beauty and value of natural stone.

The main types of stone used to create sinks and bathtubs are onyx, marble, granite, travertine, sandstone, and soapstone. Special stones like river rock and petrified wood are less common, but welcome additions to the collection. Here is a bit of information on each of these beautiful natural materials.

ONYX

Onyx is a smooth stone. Its surface can be highly polished. Behind the shine lies a crystalline structure and intense veining. These factors make each onyx sink completely unique. No two onyx sinks will match, but any two pieces made from the same type of onyx will go together perfectly. Onyx comes in three types: Multicolor, Honey Onyx, and White Onyx.

MULTICOLORED ONYX it ranges from pale green with few streaks or color variations to reds, browns, and oranges in patterns reminiscent of a Jackson Pollock painting.

HONEY ONYX it is more uniform in coloration than multicolored, but may still contain swirls, streaks, or spots. Their colors range from off-white/pale yellow to brown/yellow.

WHITE ONYX it also contains many color variations. Sometimes this stone is almost pure white with little variation in veining. It may also contain deeper white, yellow, reddish or rusty veining spots.

MARBLE

Marble comes in all colors from pure white to pure black. In the middle are yellows, browns, reds, greens, and blues. Each of these marble colors also ranges from nearly solid in color to extraordinarily veined and figured, making it one of the most beautiful and expensive materials in the world. All of these stones have color anomalies, nonstructural fracture lines, and inconsistent veining.

LIMESTONE

Limestone is a sedimentary rock made of calcite. Formed when seas and lakes evaporated, the stone often contains the fossil remains of sea creatures. Usually there are some voids on the surface of the stone. When limestone is used to create a sink, these voids should be filled with a mixture of stone dust and epoxy that closely resembles stone.

STINK

A form of limestone, travertine often forms near bubbling mineral springs. Trapped gas bubbles create a pitted surface. These wells can be filled with an epoxy resin mixed with stone dust to match the stone. Filling in the small holes and pits gives the travertine a more finished look. Polished travertine is a beautifully refined sink.

SANDSTONE

A sedimentary rock, sandstone was created when sand was deposited in estuaries and tidal flats eons ago. Sandstone contains random concentrations of minerals that appear in the stone as colored spots, freckles, or patches. The appearance of these mineral inclusions is a natural expression of this unique material. All sandstone vessels have some degree of anomalies.

BLACK GRANITE

At first glance, some black granites appear to be solid black, but upon closer examination, you will find that even the blackest granite contains small, irregular flecks of gray, silver, gold, or copper colored mineral deposits. Black granite is an igneous stone (formed from magma) and comes in many varieties, from the very fine-grained absolute black that looks almost like obsidian (volcanic glass) to the foamy-looking grandiorite, which isn’t actually a granite but is often sold as granite.

GREEN/GRAY GRANITE

The green and gray granites come from boulders that have developed naturally eroded exteriors over millions of years. The color is highly variable from pale green to dark slate green. There are usually some whitish inclusions as well as some pitting on the polished surface. Depending on the shape, part of the worn face may wrap around the polished edge.

PETRIFIED WOOD

This semi-precious material is actually a fossil created when trees are buried under mud. Wood decays and minerals invade the cavities between and within the cells of the natural wood. Jasper, quartz, and even opal can sometimes be found in fossilized wood. It is usually brown, but it can be gray or green. A limited number of sinks are made of this special material.

RIVER ROCK

Small, rounded boulders are excellent for sinking boats. Usually granite, they start out almost the right way, last forever, and are infinitely re-polishable. Some sinks are carved directly from the whole rock, others are made by cutting the rock in half, resulting in a matching pair of sinks.

When creating a sink from any type of stone, there will always be differences in texture, grain, and color in different parts of the piece. In a manufactured object, these kinds of variations are often considered flaws, but in natural stone, these enhanced areas of coloration, rough textures, and dramatic fault lines are a sign of the individual character of products made not by machines, but by the earth itself.