Answer:
It will be small.
Explanation:
When magma or lava cools, then crystals will form due to the solution being highly saturated. However, if the lava/magma cools rapidly, then the crystals won't have very much time to form, so they would be incredibly small.
Though, if the magma or lava cools slower/slowly, then the crystals have time to form, thus making them larger.