Here is the story:
The love between Antony and Cleopatra is a legend. But, that’s only half the story…
their love was quite competitive. Both trying to outdo one another.

And that’s just the beginning…this 2,000 year old tale tells of her other love – pearls.
According to legend, Antony was smitten by Cleopatra, maybe overwhelmed, maybe possessed.
Anyhow, Cleopatra was the one in control of the situation. Antony would do anything to win Cleopatra.  Celebrations, extravagant feasts, banquets would he provide during this courtship. Never letting on that any of these celebrations impressed her.

More details in a moment. But first, remember that she had a relationship with Julius Caesar. She had a son, who she claimed came from their union. Julius Caesar refused to make him his heir. Cleopatra lived in Rome until Caesar’s assassination. She then went back to Egypt and promptly had her brother poisoned. He was in her way.
After Caesar’s death Antony ruled one half of Rome. It seems Cleopatra had coveted the Empire since her days with Caesar. She might have been more in love with Rome than with Marc Antony.

In any case, the seductress that she was, loved to ridicule him. She always had the upper hand. Cleopatra would never let on that Antony impressed her. She ridiculed him and made fun of his efforts to win her favor.

 One day Cleopatra declared that she could out do Antony. Cleopatra wagered that she would spend 10 times more on her feast, than he ever did. Antony rose to the challenge. He countered her bet. He wagered that she would not be able to win.

Providing Antony with a feast fit for a king, she appeared before him wearing with a fantastic pair of pearl earrings. These pearl earrings were described by Pliny to be "two most precious pearls, the singular and only such jewels in the world, and even Nature's wonder."

Antony was not impressed with this feast, knowing that he had provided many celebrations far in excess of this one. Asking her how much she spent, Cleopatra exclaimed that she had spent over ten millionsesterci (an amount equal to a kings ransome)

To prove herself the winner, Cleopatra removed a pearl from her ear, dissolved it in a chalice of vinegar and toasting his good health, drank it down. A kingly fortune in a single swallow. She began to remove the other pearl; but, the judge of the contest would not allow it. He declared Antony the loser.

Pliny mentions that the remaining pearl was cut in half and made into earrings for the statue of Venus, goddess of Love, in the Pantheon Temple of the gods, in Rome. Immortalizing the bet.