Read it through once

We saw the day's output—shining little nests of diamonds, distributed a foot apart, along a counter, each nest reposing upon a sheet of white paper. That day's catch was about $70,000 worth. In the course of a year half a ton of diamonds pass under the scales there and sleep on that counter; the resulting money is $18,000,000 or $20,000,000. Profit, about $12,000,000.