How Much Gold Is There in a $7,000 Rolex?

The villain of an old Bruce Willis adventure movie said that money will always be paper, but gold will always be gold, and given our permanent fascination with that metal, let's say he was right. Luxury items constantly use it, but the question is: in what amount? For example, a $7,000 Rolex combines diamonds, gold, silver, and other metals. How much gold could we extract if we take the trouble to separate and purify?

Determining the value of a precious object is a complex task. In fact, television has explored that process to exhaustion, with programs about valuations and famous pawn shops in Las Vegas. Finding economic salvation in an old drawer is a very tempting possibility… but nothing stops us from following another path in the name of science. On the What's Inside channel, they decided to do something that (once again) upset their followers: Destroy a Rolex, which depending on its general condition and the region can be worth between 7,000 and 10,000 dollars. This happened in August of last year, and with the corpse of the watch at their disposal, they had another idea: send the pieces to Cody's Lab to confirm how much gold is in them.

The first step was to use an X-ray gun (read Portable XRF spectrometry) to separate the parts with a higher concentration of gold, in this case 18 karats (75 percent gold, and the rest silver). The gross total was 16.5 grams, and after deducting both the weight of the diamonds and the percentage of impurities, Cody calculated about 12 grams of gold. In the next phase, the gold had to be dissolved in hydrochloric acid and bromine as an oxidant, a process that took a couple of days. Then he heated the solution (with a little extra water) to separate the bromine, and applied a bit of sodium metabisulfite, thus starting the precipitation of gold. The dark brown powder was melted into a small button, and the final mass was 10.94 grams, not far from the initial calculation.

The last step was to separate the diamonds (which survived the whole adventure without problems) and the silver. He decided to leave the silver in powder form because the amount is very small, and his furnace would evaporate it completely instead of melting it. Unfortunately, Cody could not find out the value of the diamonds, but the final number is one dollar in silver, and 465 dollars for the gold. Compared to the 7,000 dollars of the Rolex... no, recovering precious metals from luxury items is no business. If you find a broken Rolex, have it repaired and sell it. There is always someone out there looking for a deal...