Part of the fun of searching for gold in California is knowing just how rare it is. The history of gold points to a lot of other unique discoveries. After all, there are metals out there even more valuable than gold. Here are a handful that are even rarer!

Iridium: Iridium doesn’t share much in common with gold, but all the metals on this list are noble metals – meaning they resist corrosion. Iridium is brittle and shares none of gold’s softness and malleability. It’s most famous for so much of it marking the K-T boundary, a layer in sediment that marks 65 million years ago. Iridium is much more common in asteroids than it is here on Earth. It’s a major piece of supporting evidence that an asteroid had a hand in killing off the dinosaurs.

1. Osmium: Osmium is two times denser than lead, and is the densest of all naturally occurring elements. It’s used in surgical implants and electronics where durability is crucial.

2. Rhenium: This is a silver metal that is sometimes used in jet engines. Isotopes of rhenium are also used in the treatment of liver cancer.

3. Rhodium: Gold and rhodium share a close relationship in jewelry, where some white gold is plated with rhodium. It improves the look of the gold. Rhodium is used in mammography systems and in aircraft parts.

4. Ruthenium: Another silver metal, ruthenium is used to harden other metals that are similar in nature, such as palladium and platinum.

5. Palladium: A component of emissions controls, electronics, and fuel cells, palladium is similar to the next entry, platinum, in many ways.

6. Platinum: Platinum is sometimes used in jewelry, but it’s often used for more practical purposes: in electronics, and in car parts such as spark plugs or vehicle emissions controls. It’s even used in drugs that help treat cancer!

Now, you won’t find these panning for gold in a river, and searching for them can prove far more difficult and costly. That’s why gold is a more cost-effective metal to seek out – this and its appeal in jewelry, of course. Learn to pan for gold, and learn about the history of gold in California, at Roaring Camp Mining!