Yellow sapphire and sterling silver ring

Sterling silver, Yellow sapphire
 Size: 19 / US 9
 Weight: 36.64g
 Ring parameters: 75mm length, 27mm width
 Stone: Sapphire 4,5x3,5mm (8pcs.)
 
 The set includes an oak box.
 
 Sapphire (from the Hebrew ספּיר - "Sapir" - from biblical texts, although the Bible rather referred to another stone - lazurite) is a type of mineral - corundum. Sapphire is any jewelry-grade corundum crystal that is not red (red corundum is called rubies). The most common sapphire is blue. Sapphire-forming corundum is pure in color. The special color is given by various impurities, such as iron, chrome.
 Iron and titanium are added to the sapphire in various shades of blue. If the crystal has an insufficient amount of such an impurity, it has a light, gray color and a lower value.
 Yellow and green colors also give an iron admixture. Pink sapphires contain chromium. If there is more chromium, the stone is closer to red and is considered a ruby.
 Purple, purple corundum has a mixture of vanadium. Such gems are traditionally less valuable.
 White sapphires are most often slightly brownish or yellowish at first. The pure color is obtained by heating them. Pure colorless corundum is very rare.
 There are also sapphires that change color in different lighting - blue in daylight and purple in artificial lighting.