Sapphire is a precious gemstone and a variety of the mineral corundum (Al2O3). It is most known for its rich blue color, though it can occur in a range of colors, except red (which is classified as ruby). The blue hue is caused by trace elements like iron and titanium. Sapphires are second in hardness to diamonds, ranking 9 on the Mohs scale, making them highly durable. They are often used in fine jewelry, such as engagement rings, due to their beauty and toughness. Symbolically, sapphires are associated with wisdom, loyalty, and nobility. The most prized sapphires come from regions like Kashmir, known for their velvety blue hue. Sapphires are also used in industrial applications like watch crystals and high-durability windows. They are found in many countries, including Sri Lanka, Myanmar, and Madagascar. Sapphire's brilliance and durability have made it a timeless and sought-after gemstone.