Skulls  are hand carved and no two are identical. About 3 - 4.25" high, diagonal 5 - 5.25".
 
Many Powerful Uses of Skulls
Connect to higher-dimensional crystal energy
Enhance meditationEnhance manifesting
Uplift and protect your surroundings
Purify your  karmic energy 
 
Clear Quartz: Amplifies energy and intention. Clear Quartz protects against negativity, attunes to your Higher Self and relieves pain. It is called the master of all healing crystals, as it magnifies healing vibrations of other crystals.