If you’ve ever Googled “weight of a gold bar” hoping for a simple answer, you’ve probably noticed that the answer depends on who you ask  and why you’re asking. A central banker thinks in 400-troy-ounce Good Delivery bars. A first-time investor might be eyeing a sleek 1-ounce coin bar. A jewellery manufacturer in Kampala might be sourcing 1-kilogram kilobars...