I listened again, he said .17 oz over 6 grams. Maybe his math / memory is off a bit, as I get 5.3 grams

One troy ounce is 31.1034768 grams, or 0.0311034768 kilograms.

The troy ounce is used in the weighing and pricing of the precious metals : gold, platinum, and silver.

A troy ounce is equivalent to 480 grains. A grain is 0.06479891 grams.