Y necklace: Usually 16 to 18 inches in length, this style of necklace gets its name from its shape which features a dangle forming a Y-shape around the neck.
Yellow gold: The most popular gold alloy made up of gold, silver, copper, and often zinc.
Yttrium: A silvery metallic element of the boron-aluminum group, found in gadolinite and other rare minerals, and extracted as a dark gray powder. Not a rare earth but occurring in nearly all rare-earth minerals, used in various metallurgical applications, notably to increase the strength of magnesium and aluminum alloys.