Realgar is a mineral composed of arsenic sulfide, known for its vibrant red-orange color. It is often found in hydrothermal veins and is associated with other minerals like orpiment and gold. Realgar has been used historically in pigments and traditional medicine, although its arsenic content makes it toxic. In addition to its aesthetic appeal, realgar is of interest in geology and mineralogy. It can form in various geological environments, often indicating the presence of volcanic activity. Due to its toxicity, handling realgar requires caution, and it is primarily studied for its unique properties rather than for practical applications.