If you read some of my blogs, you'll notice that I study history a lot. I was searching for old currencies used in South Africa one day a few years back & discovered something which was called by indigenous people of KZN as "ukhence" or "inkence". To this day, a colloquial word for money by indigenous people is "inkence". This currency was said to be so popular among indigenous people that it infiltrated popular culture of the time viz. "Wangishaya ngokhence." Officially called Stratchan & co. token coins, it was likely the first mainstream currency used by indigenous people other than cattle, tools, weapons & crops even though it was said to be minted in England.
They claim the hole was so indigenous people could wear it with beads but maybe it was also for the practical purpose of saving metal to make the coins.
The Strachan & Co. token coins are South Africa's first circulating indigenous currency (they circulated for nearly 60 years from 1874).