During the Middle Ages, sapphires and rubies initially adorned the engagement ring, while diamonds were incorporated in the 15th century. The earliest written record of the use of a diamond in an engagement ring was in 1477 by a Dr. Moroltinger, who was advising the future Holy Roman Emperor Maximillian to have a ring set with a diamond for his betrothal to Mary of Burgundy. Resisting fire and steel, diamonds stood for the fortitude of a lifelong partnership. Early cutting techniques caused gems to look dull and even black, according to the Gemological Institute of America (GIA), which is considered the world's foremost authority in the grading and identification of diamonds and other gem material. Compensating for these lackluster stones, goldsmiths designed elaborate settings, composed of such romantic notions as rosettes and fleur-de-lis, symbolizing the bride's purity.

More ephemeral than the diamond ring, the rush ring was hastily made from leaves or grass and lasted in many cases as long as the short-lived engagement. A more enduring and popular 16th century ring, the fede (Italian for faith) betrothal ring signified a marriage's immutability in its central image of two clasped hands.

With the discovery of diamonds in Brazil in the 18th century, diamond jewelry became more readily available, and diamond cluster engagements rings were in vogue. A common cluster design consisted of small rose-cut diamonds arranged around a larger center stone.

Widespread wealth, initiated by the 19th century's Industrial Revolution and the rich supply of newly discovered African diamond mines, made diamonds available to a greater public. Diamond experts at GIA also note that this period was marked by revolutionary developments in cutting and polishing, resulting in diamonds revealing a brilliance greater than any other gem. The diamond now could stand alone, and thus, the solitaire engagement ring became fashionable.

The simple elegance of the classic Tiffany mounting, introduced in 1886 by Charles L. Tiffany, offered an ideal complement to the beauty of the diamond. With the diamond set high in an open, six-prong mounting, the design permitted greater amounts of light to enter the gem, allowing it to exhibit maximum brilliance. Given all the choices that are available to couples today, not only can they choose an engagement ring that represents a centuries-old symbol of love and tradition, but more importantly, a ring that is a personal expression of themselves.