Not both gold and silver becoming almost worthless at the same time, but just back in the late 90's silver was down to $4-something an ounce. At one point in the 70's I believe, it was up to at least $50 an ounce, but then supposedly this wealthy oil guy dumped a bunch of silver onto the market(from what I read), and it caused the silver prices to plummet. I was just looking into silver a few days ago and it was mentioned that silver had been up to the mid to high $40 range not to many months ago, but then the gov't did something that artificially caused the prices to drop way back to the $29-ish range per ounce. The moral of the story, is that apparently(for some reason), silver is prone to the wild ups and downs occasionally. I dont know of too many other common precious metals that plummet at times like silver has, but then again, I havent watched charts back further than a few decades.
I remember back in the 90's, I was trying to convince my family that silver MUST go up in price again at some point, as it was really low at that time($4.70 or so), but after looking at the charts over the past 20 years, they were hesitant, besides, at that time you could reliably invest in safe mutual funds that paid 12-15% annual rates, so they werent interested at that time. So we didnt do it.
Whats even more interesting to watch is the PGM's(platinum group metals). They are almost always found together in ores, and are difficult to separate. They consist of 1. Platinum, 2. Palladium, 3. Rhodium, 4. Ruthenium, 5. Osmium, 6. Iridium
^The PGM's are far more rare than silver, and most if not all of them are much more rare than gold. I looked into the PGM charts over 10-15 years back in around 2002, and at that time Rhodium had gone from a high of around $3,000+ down to about $250 an ounce. That to me seemed like a no-brainer investment in 2002. Well, sure enough, in just 4-5 years Rhodium was back up above $5,000 an ounce!
But its not just Rhodium thats all over the place, the PGM charts over the last 2 ten year periods look like radio frequency graphs, with each PGM replacing another one as the most or least expensive! They can be all over the place. But back in 2002, I believe Palladium was the cheapest, or one of the cheapest, at not much more than $100/oz, but now its up to around $700 or so too.
As of now, the PGM's are crucial to helping cleanse the environment because they are catalysts used in catalytic converters and other anti-pollution devices. That and there isnt exactly a huge supply of them. The only downside is that a few PGM's are the most dense(heaviest) metals/elements on the entire periodic table, with Osmium and Iridium battling it out as the heavist... So an oz. of Osmium will look much smaller than an oz. of silver for instance.