サファイア

Sapphire is a precious gemstone that belongs to the corundum mineral family, with the most famous variety being its rich blue form. While blue is the most well-known colour, sapphires come in a range of colours, except red (which is classified as ruby). Sapphires are highly valued for their durability, with a hardness of 9 on the Mohs scale, making them ideal for daily wear in jewellery. Historically, they have been associated with wisdom, nobility, and purity. Sapphires are considered one of the "big four" gemstones, alongside diamond, ruby, and emerald.