Betrothal rings were used during Roman times, but they weren’t the diamond rings we know today. Designed as a key, they symbolized a woman unlocking her new married life and were usually made from brass, bronze or iron.
The tradition of the key spread though Europe and the following words were added to the wedding ceremony around the sixth century: “I give thee my daughter to be thy honor and thy wife, to keep thy keys, and to share with thee in thy bed and goods.”
The first well-documented use of a diamond ring to signify engagement was by the Archduke Maximilian of Austria in imperial court of Vienna in 1477, upon his betrothal to Mary of Burgundy. Many royal families gave rings with gemstones each signifying and holding different meanings: The ruby stood for love; the emerald, home; and diamonds for fidelity and durability.
As diamonds became more available in Europe in the 18th century they became the stone of choice. In 1886, the Tiffany setting suspended the stone above the band allowing more light in and adding sparkle.
In the 1930 the trend was picked up in the states when DeBeers began a major advertising push. N.W. Ayer convinced Hollywood actresses to wear diamond rings in public and encouraged fashion designers to discuss the new “trend,” according to Slate.com. It worked. From 1938 and 1941 diamond sales went up 55 percent.
And it continued to grow. By 1965 80 percent of American women had diamond engagement rings.