See [www.memri.org]
"Koranic Verses Indicate Clearly That Coins Were Used in Egypt in the Time of Joseph"
"Studies... Have Revealed That What Most Archeologists Took For a Kind of Charm, and Others Took For an Ornament... is Actually a Coin"

"According to Dr. Thabet, his studies are based on publications about the Third Dynasty, one of which states that the Egyptian coin of the time was called a deben and was worth one-fourth of a gram of gold. This coin is mentioned in a letter by a man named Thot-Nehet, a royal inspector of the Nile bridges. In letters to his son, he mentioned leasing lands in return for deben-coins and agricultural produce.

I've seen a suggestion that the 'coins' look as though they are from the Hellenistic/Roman period.

Doug Weller

Director The Hall of Ma'at
Doug's Skeptical Archaeology site::
[www.ramtops.co.uk]