The term 'A Gem in a Setting By Itself' can be broken down into three crossword solutions: SOLITAIRE (9 letters), OPAL (4 letters), and STONE (5 letters). SOLITAIRE is a type of card game that is played by one person. An OPAL is a precious gemstone that is known for its rainbow-like colors. A STONE is a naturally occurring solid material composed of minerals. Therefore, the phrase 'A Gem in a Setting By Itself' can be interpreted as a single precious gemstone, such as an OPAL, set in a piece of jewelry all by itself.