78.) Platinum

Atomic Weight 195.078
Density 21.09 g/cm3
Melting Point 1768.3 °C
Boiling Point 3825 °C

Pure platinum mesh, like mosquito netting except more expensive, is one example of platinum's use as labware impervious to nearly all chemical attack. It is also used in coins, which are similarly expensive. Platinum is extremely valuable for multiple different reasons; it isn't just a noble metal like silver or gold, it is one of the best-functioning catalysts in existence, thus why it would be used in a mesh like the one above. The idea is to react all the harmful material that passes through it into safe by-products using the platinum mesh as a form of exposing more surface area. That being said, platinum is also among the more dense metals, at a full 1.6x denser than gold. It doesn't help that it's also more expensive per gram and is required in more scientific applications than gold, which is mainly consumed through the electronics industry rather than the catalysis industry. Essentially, at this point in scientific progress, it's almost impossible to catalyze certain valuable reactions like hydrogen production or toxin decomposition without using platinum. Which is interesting, because...

There's really no reason to ever make or buy platinum jewelry, unless you have such a strong desire to waste money and scientific resources. It's rarer than gold, denser and more expensive per gram. Its properties are so extreme as far as nonreactivity and catalytic potential that they are absolutely wasted as a piece of jewelry, which could just as easily be gold or silver to achieve the same effect. At least platinum coins can be cleaned and melted to reclaim the platinum.

Platinum is much more useful in an application like this which you may have heard of: automobile catalytic converters. This is a full diagram of how it works, and trust me when I say that mesh is massive and contains a great deal of platinum. If someone intelligent is scrapping your car, they'll go for this first. It turns carbon monoxide into dioxide, it coverts nitrogen oxides into nitrogen, and catalyzes breakdown of the many hydrocarbons that are emitted with car exhaust into mostly carbon, carbon dioxide, or water. Platinum is the most powerful element in the known universe at keeping people safe!! Oraoraoraoraoraora!!!!!!