The Strength and Hardness Ratings of Granite and Marble
Selecting the right counter top stone for your home depends on numerous factors, including your budget and design choices. Another important factor is stone strength. Each natural stone has a strength rating often referred to as its Mohs hardness. The Mohs scale of mineral hardness was developed to identify the strength and hardness of any natural mineral.
For instance, if a stone has a Mohs hardness of seven, then that stone is solid enough to scratch another stone with a rating of six or lower. The information below gives homeowners an brief overview of the strength attributes of two popular stone types and their respective Mohs hardness ratings.
Granite
If you are wary of scratching or cracking your stone counter tops, you may consider installing granite. Granite is a very hard stone and resistant to damage. Though the composition of various granite colors and varieties will vary from slab to slab, granite is generally is made up of a quartz, feldspar and an assorted variety of minerals, evoking a gritty look. However, granite is still vulnerable to staining. Granite has a Mohs hardness rating of seven.
Marble
Marble is limestone that has been compacted and heated over millions of years. As a result, marble is less porous and slightly stronger than limestone, but still less durable than granite. Depending on the limestone and the mineral combination within the marble, most marble rates from three to five on the Mohs hardness scale.