Sand or dregs pink In rivers or waterfalls usually comes from iron or clay mineralsThis color is common in nature.

If sand It was heated and then changed color and smelled like sulfur., it's a sign of existence iron or sulfide minerals. Gold is odorless, non-smoker, and colorless When heated.

Simple check method:
When sand is washed and stored in water, Red is usually washed away, while gold (if any) will be Stay heavy and stay at the bottom..

Pink sand and sulfuric smell indicate iron mineral deposits, not gold.