Additionally, some foods can have a laxative effect that speeds up digestion, resulting in diarrhea. Under normal circumstances, bile turns dark brown as it passes through the digestive tract. But ...
A hand-held flashlight reveals the green color of a rough emerald from the Coscuez Emerald mine in Colombia. Photo by Eric Welch/GIA. Emerald is the green to bluish green variety of beryl, a mineral ...