admin
(No.2, Vol.4, Mar-April 2014 Vietnam Heritage Magazine)
Cave pearls in Son Doong Cave in Quang Binh Province, Central Vietnam. Cave pearls are formed when water droplets containing calcite fall and hit a grain of sand on the ground, causing the calcite to stick to the sand. Over time they get bigger and bigger.
Photo: Ryan Deboodt, August, 2013