Calcite Rough Crystal not only increase and amplifies energy, but also raises learning abilities, so makes it a great stone for students, especially younger students who can be more prone to distractions.  The blue variety also soothes frayed nerves and lessens anxiety and is a good stone used when recuperating, as it clears negative emotions promotion physical healing. Further properties include enhancing intuition and improving inner sight.  Each stone weighs approx 30-70g. Size and shape may vary. Stones sold individually