This Katanga cross appears to be authentic.
This X-shaped ingot of cast copper, usually referred to as a Katanga Cross, comes from Katanga, a rich mining region in the south-eastern portion of the Democratic Republic of Congo (formerly Zaire) along the Kasai River. It is the classic currency associated with the region and probably the best known form of African tribal currency. For centuries these crosses served as indications of wealth and were used for dowry payments and trade. Since they have been found in burial sites, they have also been associated with funerary rituals.
The most common forms of traditional money in Africa were made of metal, either forged or cast - which had the great advantage of storing wealth in a form that might be melted down and refashioned into a tool or a weapon if the need arose. Try doing that with a stock certificate!
The Congolese regarded the non-ferrous metals -- copper, lead, and tin -- as very precious materials. Objects made of these metals were a widespread means of exchange and important in settling social contracts, such as marriage. Early in the 20th century, one cross might purchase five to six chickens, two lengths of good fabric, eight to nine pounds of rubber, or six axes.
The Katanga region declared its independence from the DRC shortly after Belgium granted the region its independence in 1960. In 1961 Katanga issued its first coins, copper one and five Franc pieces for circulation. A gold version of the five Franc coin was also issued as a non-circulating commemorative. In homage to the heritage of the region, the coins pictured the Katanga Cross. After two years of fighting Katanga was forcibly reunited with the DRC in 1963.