Commercial vs. Geologic Definitions of Natural Stone

The granite slabs many American homeowners have chosen for their kitchen and bathroom countertops may not be considered granite by scientists in the fields of geology, mineralogy, and petrology. Even quarry workers and masonry experts may take a look at finished granite and call it by different names such as gneiss, anorthosite, diorite, and many others. However, they may also be determining the geographic provenance of the stone and its various industry names. Very dark granite quarried in the Americas is known as Black Granite, but it’s called Black Pearl if extracted from India and Black Labrador when it comes from Norway. To a geologist, these are all anorthosite igneous rocks. The naming of natural stone for construction purposes doesn’t follow scientific convention because it would turn out to be complicated. When you get extremely technical about the origins of natural stone, some types of fine marble would have to be called limestone. Similarly, some of the most expensive granite quarried from Brazil would have to be called quartzite. When it comes to choosing tiles, panels, and slabs, it’s easier to follow the groups determined by the natural-stone industry. Granite In scientific notation, true granite has the color and patterns of chocolate chip ice cream. If it’s black as the night, it’s actually basalt, and it’s diorite when it presents a very fine grain with a touch of brown specks. Like all other types of natural stone, it’s vital to clean granite countertops regularly with a stone-safe granite cleaner. Granite Gold Daily Cleaner® is the perfect solution for caring for natural stone. Limestone Earth scientists know limestone as a family of rocks primarily made of calcium carbonate. To a certain extent, limestone is biochemical since this is the primary material of scallop shells. In the Israeli and Palestinian regions, limestone is known as kurkar, which has a higher quartz content approaching marble, although it’s rarely white. Marble In essence, marble is limestone that underwent an additional metamorphic process resulting in crystalline calcium carbonate. Onyx This interesting and very colorful stone is most commonly used for jewelry applications, and it’s composed of silicate minerals plus quartz that has crystallized various times. Quartzite Through various geologic processes, sandstone with very high quartz content will eventually turn into quartzite, scientifically known as phyllite. As previously mentioned, granite with very high quartz content may actually be quartzite, one of the strongest natural stones. Sandstone Quite a few surface minerals, most of them mixed with sand that has been fused into rock, make up sandstone. The proper scientific description would be clastic sedimentary rock. Slate Geologically speaking, slate is shale rock or siltstone, which results from sedimentary processes involving clay minerals and volcanic ash. Soapstone Based on petrology, soapstone is talc schist material with an interesting surface that feels soapy to the touch. Soapstone is a hard/dense type of natural stone. Travertine This limestone gets its attractive patterns and colors from mineral processes that normally take place in hot springs. At many travertine quarries along the Mediterranean, blocks of exotic marble are often extracted. The composition of travertine is primarily aragonite and calcite. If you need a high-quality granite countertop cleaner or other products that are safe to use on these and other types of natural stone, reach out to Granite Gold® today. One of our knowledgeable representatives would be happy to take your call at 1-800-475-STONE (7866). If you’d like monthly tips on caring for natural-stone and quartz surfaces, you’ll also want to sign up for our newsletter right away.