What are energy minerals?

What is Gibb's free energy of minerals & what is its significant?

• during metamorphic reaction minerals are become stable when their Gibb's free energy are negative

• Answer:

  Let me see here. If I remember correctly: delta G = delta H - T delta S. This is the formula for Gibb's Free Energy. Delta G is Free Energy, delta H is enthalpy, delta S is entropy and T is the temperature in degrees Kelvin. Enthalpy is energy not available to do work, so it is not part of the calculations. Entropy is the tendency of the universe to go to randomness, which increases as the temperature rises. Since the formation of a mineral is a more orderly state than its liquid counterpart, the entropy (of a system) must be negative. Since temperature remains constant in a phase change (like when a molten state becomes a solid state), a lower entropy must be equal to a lower Gibb's Free Energy, which means that Gibb's Free Energy must be negative..