Gemstone characteristic that lends value to a gemstone. Apart from jewelry, from earliest antiquity engraved gems and hardstone carvings, such as cups, were major luxury art forms. A gem maker is called a lapidary or gemcutter; a diamond cutter is called a diamantaire. The traditional classification in the West, which goes back to the ancient Greeks, begins with a distinction between "precious" and "semi-precious"; similar distinctions are made in other cultures. In modern use the precious stones are diamond, ruby, sapphire and emerald, with all other gemstones being semi-precious. This distinction reflects the rarity of the respective stones in ancient times,
Traditional Vietnamese wedding comprise the Western white wedding gown, a second Western dress to be worn at the end of the evening during the dancing, and a third traditional Áo dài to be worn during the traditional table visits to personally thank the guests for coming. While most Vietnamese are Mahayana Buddhists, a significant number are Catholic. However, this does not change the traditional Vietnamese wedding. Vietnamese Catholics still incorporate all parts of the wedding ceremonies and reception. The only difference may lie in the ancestor worship at each newlywed's house. Because Catholicism does not condone such worship, this ceremony is often omitted