Well, back in the old days, with gold bonded dies in ceramic housings almost all ICs had good value. This was in 1975 or so. Back in those days they also plated

Well, back in the old days, with gold bonded dies in ceramic housings almost all ICs had good value. This was in 1975 or so. Back in those days they also plated 30-50 micro inches on fingers. Then gold hit the roof, and all parts had gold "adders" = increased prices along with gold. They would like to use 1 micro inch plating on fingers, but copper and gold are totally miscible(same series in the periodic table) and with 1 micro inch the copper would migrate to the plated surface by diffusion and corrode with the CO2 in the air = green shit. Then they found that 5 micro inches of nickel plating would block diffusion and they could use 1 micro inch gold over nickel, so by 1985 or so, fingers began to decline. They are still valuable, but nor worth $100 a pound like the old military trimmed fingers were. So find scrap buried in the 1970s, and you might have a shot - but only if you get a lot of boards, refrigerators had very little gold.