What is pH of an enzyme ?

most enzymes' optimum pH is neutral or close to neutral, like amylase found in saliva, which has an optimal pH = 6.8. Some enzymes prefer a more drastic pH, like pepsin, which can have an optimum pH of 1.7 to 2. Sometimes enzyme pH optima depends on where the enzyme is found.

pH is a measure of how acidic or alkaline a solution is.

it cools slower in the earth meaning the crystals have more time to form than lava on the surface