One time, many years ago, I went to Pakistan via Hong Kong. In Hong Kong, I noticed that they had strings of freshwater or Biwa pearls very cheap. The kind that look like rice krispies. Those are the only ones that Pakistanis believe are genuine pearls, whereas they think all round pearls are fake. And so the rice krispies pearls sell for quite a lot more in Pakistan than in Hong Kong. We found out the going rate by weight for pearls in Lahore. The jewellers there measure using indigenous units called
rattis and tolas. Hmmn.
Depending on how much the pearls in HK weighed... Ka-ching!
. I decided to make a side trip back to HK to invest in some pearls. Got to HK. Went into a jeweller's to buy some.
In HK, they are only sold by the string, and not by weight. Couldn't get them to weigh them. "No, we only sell by the string." Went to several shops. Same intransigence. Finally, one shopowner agreed to weigh them on the diamond scale. Which is calibrated in carats...
So first we figured out how many carats in the average string, then converted that to grams. Then converted that to troy ounces. Then converted that to rattis and tolas. Then I had to convert the cost in HK dollars into US dollars, US dollars into Pakistani rupees, to arrive at the cost per tola of pearls on a string. Thank God calculators are cheap in HK, and remember in those days there was no internet or Wikipedia to look things up on!
Didn't have much investment money, but did break even on the trip, covering the costs of airfare and hotel, etc. So I got a little holiday out of it. Decided not to make a business of it though. Pakistani (and other South Asian) jewellers are the sharpest dealers in the world.