A3 books The essence of precious stones The essence of precious stones. Anneke Agterberg's microscopic photographs allow you to see and experience the essence of 52 precious stones. Each stone (from strawberry quartz to sunstone) has its own unique color explosion and healing potential. The accompanying text gives you a nudge in the right direction. Confrontational, affirming, comforting... exactly what you need at that moment. With their essential message, the precious stones help you gain insight into what's going on and how best to deal with it.