Star ruby is a unique variety of the mineral corundum, which is known for its striking red color and a star-like phenomenon called asterism. This effect occurs when light reflects off needle-like inclusions of the mineral rutile within the stone, creating a star shape that appears to move as the gem is rotated. Typically found in regions like Myanmar and Sri Lanka, star rubies are highly valued in the gemstone market. Their vibrant color and captivating optical effect make them popular choices for jewelry, especially in rings and pendants.