What is granite?

Hint: Plutonic rocks basically are the igneous rocks which cool and solidify from a melt in the earth’s crusts.
Acid rocks are the igneous rocks with above $60%$ silica $(Si{{O}_{2}})$.
Common Acid Rock is granite.

Complete answer:
Granite, igneous rock that is rich in quartz and feldspar; this is the most common plutonic rock in the Earth’s crust, which is formed by the cooling of magma (molten silicate) at depth.
Granite has a typical chemical composition of $70-77%$ silica,$11-13%$ alumina, $3-5%$potassium oxide,$3-5%$soda,$1%$ lime,$2-3%$ total iron, and less than $1%$ magnesia and titania.
It is one of the oldest and most sustainable construction products available. It has become the prime material of choice for today’s luxury homes and offices because of its durable beauty, and because no synthetic material is yet capable of competing with its elegance and performance.
Granite consists of feldspar, quartz, some dark—coloured minerals, sand and mica. The main chemical propositions of the granite are $Si{{O}_{2}}(65%\sim 70%)$, a little of$A{{l}_{2}}{{O}_{3}},CaO,MgO$ and $F{{e}_{2}}{{O}_{3}}$, so that's why the granite is called acid rock.
The characteristics of granite are as following:
Suitable for decoration.
Intense hardness
Very Durable
Resistant to acid and erosion.
Poor fire resistance

Note:
Granite is a common stone on Earth, and constitutes most of the crust (the outer layer of the Earth). It is generally found in the continental plates of the Earth's crust.
India had \[37,426\] million cubic metres of granite reserves and a fifth-largest export of processed products.