Tanya Dellaccio 
Tunneling for Turquoise [PDF ebook] 

The opaque, blue-green gemstone called turquoise has been mined since the time of the Ancient Egyptians. In this interesting and informative book, readers will learn about the properties of turquoise, how it’s mined, and what it has been used for historically. Full-color photographs add interest to the comprehensive content. The attention-grabbing subject matter delivers the lessons of elementary science curriculum in an imaginative and exciting way.