The Marlborough gems were a large collection of jewels (cameos and intaglios) assembled by several Dukes of Marlborough. The collection was composed of more than 730 carved gemstones, including garnet

Garnet

The garnet group includes a group of minerals that have been used since the Bronze Age as gemstones and abrasives. The name "garnet" may come from either the Middle English word gernet meaning 'dark red', or the Latin granatus , possibly a reference to the Punica granatum , a plant with red seeds...

s, sapphire

Sapphire

Sapphire is a gemstone variety of the mineral corundum, an aluminium oxide , when it is a color other than red or dark pink; in which case the gem would instead be called a ruby, considered to be a different gemstone. Trace amounts of other elements such as iron, titanium, or chromium can give...

s, emerald

Emerald

Emerald is a variety of the mineral beryl colored green by trace amounts of chromium and sometimes vanadium. Beryl has a hardness of 7.5–8 on the 10 point Mohs scale of mineral hardness...

s and many cameos. The most famous cameo, and the Duke's favourite, was The Marriage of Cupid

Cupid

In Roman mythology, Cupid is the god of desire, affection and erotic love. He is the son of the goddess Venus and the god Mars. His Greek counterpart is Eros...

 and Psyche.

The Marlborough gems were sold by the 7th Duke of Marlborough at auction to raise money for the maintenance of Blenheim Palace

Blenheim Palace

Blenheim Palace  is a monumental country house situated in Woodstock, Oxfordshire, England, residence of the dukes of Marlborough. It is the only non-royal non-episcopal country house in England to hold the title of palace. The palace, one of England's largest houses, was built between...

, the ancestral home.