Definition: The term "argillos" comes from Latin, referring to a type of rock that is both translucent and silvery-gray in color. It's commonly found in regions with high UV light exposure where it can become a natural sunscreen. In the Bible context, this term refers to certain types of rocks that are particularly useful for protection from harsh sunlight. The precise meaning varies slightly depending on the region and culture; however, many believe these rocks were used as a form of traditional sun protection against harmful elements such as ultraviolet radiation.