An engagement ring, also known as a betrothal ring, is a ring indicating that the person wearing it is engaged to be married, especially in Western cultures. A ring is presented as an engagement gift by a partner to their prospective spouse when they propose marriage or directly after a marriage proposal is accepted. It represents a formal agreement to future marriage. In most Western countries, engagement rings are worn mostly by women, and rings can feature diamonds or other gemstones. The neologism mangagement ring is sometimes used for an engagement ring worn by men. In some cultures, including Northern Europe, both partners wear matching rings, and engagement rings may also be used as wedding rings. In the Anglosphere, the ring is customarily worn on the left hand ring finger, but customs vary considerably elsewhere across the worldEmerald is a gemstone and a variety of the mineral beryl (Be3Al2(SiO3)6) colored green by trace amounts of chromium or sometimes vanadium.[2] Beryl has a hardness of 7.5–8 on the Mohs scale.[2] Most emeralds are highly included,[3] so their toughness (resistance to breakage) is classified as generally poor. Emerald is a cyclosilicate.