For today's #metalmonday, let's take a look at some of the world's rarest naturally occurring metals. The world's rarest naturally occurring metal is astatine. However, it's important to note that astatine is not a metal in the traditional sense; it's a radioactive element and is classified as a metalloid. Its rarity is due to its extremely short half-life, which makes it one of the least abundant elements in the Earth's crust. Astatine is so rare that less than 1 gram is thought to exist naturally in the Earth's crust at any given time. In terms of rare precious metals, rhodium and iridium are among the rarest. Rhodium is a silver-white metallic element that is highly reflective and resistant to corrosion. It's used in high-performance alloys and as a catalyst. Iridium, another metal in the platinum group, is the most corrosion-resistant metal known and is used in high-temperature and corrosive environments, as well as in some types of spark plugs and in the production of crucibles for crystal growth. These metals are not just rare in terms of their abundance in the Earth's crust but also in terms of their production and availability in the market. #materialscience #metals #elements
