These pumice stones come from volcanic activity in Guatemala. It is a perfect material for exfoliating hard skin on your feet. After a hot footbath, scrub gently with the pumice stone, and your feet will feel 10 years younger. These naturally occurring volcanic pumice stones are formed when volcanic lava mixes with water and solidifies. When lava solidifies, gas bubbles contained in it are trapped in the rock. A pumice stone is formed! Because of these gas bubbles, the stones are very light and they float on water. It is said that ancient Mayans used these volcanic stones for construction purposes. ● Each stone measures approximately 3-1/4'' high x 2-1/4'' x wide x 3/4" deep. ● 12 Piece Display Box Measures 4'' high x 9-3/4'' wide x 7-1/2'' deep. Fair Trade imported from Guatemala. "From The Mayan People To You" - De La Selva, located near La Antigua in San Juan del Obispo Guatemala, is a producer and global exporter of high-quality Mayan and Guatemala products.