The given statement is True.
Minerals will form from lava as the lava cools down. The rate by the lava will cool down determines the crystal size in the minerals.
If the sticky magma cools quickly, then it forms small crystals.
If the magma is trapped for a longer time inside the rock, then it forms larger crystals.
The time duration in which the magma cools down determines the size of the crystals.
