Granite has a Rockwell hardness of 7, making it one of the hardest rocks. Talc scores a 1 on the scale, being extremely soft, whereas a diamond is rated at 10, the hardest known mineral.
Granite typically has a hardness ranging from 6 to 7 on the Mohs scale of mineral hardness, making it relatively hard and durable. This hardness level allows granite to resist scratches and abrasion, making it a popular choice for countertops and other surfaces that endure daily wear and tear.
Granite is not assigned a number on the Mohs scale of hardness. The Mohs scale is a measurement of the relative hardness of minerals. Because granite is a rock composed of a variety of minerals, only the individual minerals which compose it have a Mohs hardness.
55-58 HRC (Rockwell Hardness) typically indicates a high level of hardness and wear resistance in metals or materials. It signifies that the material has been heat-treated to achieve this level of hardness, making it suitable for applications requiring durability and strength, such as cutting tools or industrial components.
Both basalt and granite are types of rock, and a rock is composed of multiple minerals - except for some rocks composed of essentially one mineral like limestone (calcite) or quartzite (quartz). Minerals are crystalline compounds with known characteristics such as hardness, specific gravity, etc Therefore the hardness of the rock depends on the exact location on the rock you are testing the hardness, as it will vary from mineral to mineral. Some minerals even have differential hardness. Granite is composed of quartz, feldspar, and usually some ferromagnesian minerals such as biotite or hornblende (depending on the definition of a granite). Basalt is composed mostly of plagioclase (a feldspar) and pyroxene. Each of those minerals has a different hardness, and geologists never use the hardness of a "rock" to determine what kind of rock it is. Basalt is usually much finer grained than granite so it would be virtually impossible to determine the hardness of the individual mineral crystals. On Moh's hardness scale, the hardness of these rock-forming minerals are as follows: Quartz 7 Feldspar 6 (depending on the species of feldspar) Biotite 2.5-3 Pyroxene 5-6 (depending on the species of pyroxene) So the hardness of a rock is determined by the minerals, and in a coarse grained rock like a granite, the hardness can vary widely. The hardest mineral in granite (quartz) is harder than the hardest mineral in basalt (feldspar), but that's not enough to say that granite is conclusively harder than basalt. The resistance to breaking of a rock (which could be confused with the apparent hardness to a non-expert) is greatly affected by fractures, weathering, induration, welding, and many other features which are independent of mineral content.
Granite is an igneous rock composed mainly of quartz, feldspar, and mica. It is known for its durability and hardness, making it a popular choice for countertops and building materials. Granite comes in a wide variety of colors and patterns, making it aesthetically versatile in design applications.
The initial load in Rockwell hardness test is 10KGf.
hardness as it is measured on a rockwell or brinell testing instrument
Rockwell hardness
The Rockwell C Hardness for a grade 10.9 fastener is 32 - 39HRC or 320 - 380Hv10
Both are two different scales of hardness measurement.
plan a fair test with timing......... bash each rock with a hammer and see which one breaks first
it is 6 1/2 in the mohs hardness scale
may be 75RHN
59RC
7
it is 90
No, because hardness is not a fundamental quality