is basalt harder than granite?

Question

pls give appropriae reasons to support ur choice...

Answer 1

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.

Answer 2

Basalt Hardness

Answer 3

This Site Might Help You.

RE:
is basalt harder than granite?
pls give appropriae reasons to support ur choice...

Answer 4

No, I would assume granite to be harder than basalt. Granitic magma cools inside the earth (intrusive), so its crystals are larger and more pronounced. Basalt cools rapidly and is extrusive, so it has smaller crystals.
Additionally, granite has more silica than basalt, and silica is a hard and strong mineral.

Answer 5

No, i assume granite is harder than basalt because:
Granite (IPA: /ˈgranɪt/) is a common and widely occurring type of intrusive, felsic, igneous rock. Granites are usually medium to coarsely crystalline, occasionally with some individual crystals larger than the groundmass forming a rock known as porphyry. Granites can be pink to dark gray or even black, depending on their chemistry and mineralogy. Outcrops of granite tend to form tors, and rounded massifs. Granites sometimes occur in circular depressions surrounded by a range of hills, formed by the metamorphic aureole or hornfels.Granite is nearly always massive, hard and tough, and it is for this reason it has gained widespread use as a construction stone. The average density of granite is 2.75 g·cm−3 with a range of 1.74 g·cm−3 to 2.80 g·cm−3. The word granite comes from the Latin granum, a grain, in reference to the coarse-grained structure of such a crystalline rock.Granite (IPA: /ˈgranɪt/) is a common and widely occurring type of intrusive, felsic, igneous rock. Granites are usually medium to coarsely crystalline, occasionally with some individual crystals larger than the groundmass forming a rock known as porphyry. Granites can be pink to dark gray or even black, depending on their chemistry and mineralogy. Outcrops of granite tend to form tors, and rounded massifs. Granites sometimes occur in circular depressions surrounded by a range of hills, formed by the metamorphic aureole or hornfels.
Here is a site where is gives comparisons between basalt and granites:
http://jersey.uoregon.edu/~mstrick/AskGeoMan/geoQuerry27.html

Answer 6

What Is Basalt

Answer 7

check a reference table for there hardness index or whatever it is called.. the higher the number, the harder it is... the numbers are relative with no units... tested on which scratches what

Answer 8

Both are igneous rocks.