The US$100,000 to Narh Global Services Ltd (NGSL) is to help it buy new washing facilities to increase the production of NGSL's alluvial properties.
It does not bear interest but the discount on shipments for Wishbone from NGSL is increased to 6% from 3% for future shipments from alluvial production.
The loan will be repaid out of increased shipments of gold.
Wishbone's chairman and chief executive Richard Poulden said: "This is a vote of confidence in one of our trusted suppliers.
"To put this transaction in context, Bank of Ghana interest rates are currently around 25% pa. In addition the company is lending to company with no proven resource, relying on our own in country due diligence and NGSL's track record as a supplier. We anticipate that we make similar investments in future".
Shares gained 9.38% to 0.875p.