Bismuth - a surprisingly rare metal

Bismuth - a surprisingly rare metal

Bismuth (Bi) is a metal (though sometimes classified as a metalloid) best known for the beautiful crystals if forms when cooled from a liquid state. Other uses for metallic bismuth are rather limited, usualy replacing lead in applications where a toxic metal is not an optimal choice, such as soldering, fishing or hunting.

Being only around as abundant in the Earth's crust as silver (Ag), such metal is not a resource to be implemented widely in such mundane tasks anytime soon.

Bismuth metal pieces.

Pure metallic bismuth is a silvery, shiny metal that oxidizes on air when heated. Otherwise Bi is classified as highly unreactive metal, just below copper and mercury. It is also surprisingly brittle and can be broken up by hand. That makes it useless in structural roles, at least in the pure, unalloyed form. Reagent grade bismuth can be bought in the form of small, needle-like drops or bigger bars that can be broken into smaller pieces.

35 gram crystal of bismuth metal.

Bismuth metal has a very low melting point of just over 270 degrees Celsius, but alloyed with other metals it can form eutectics as low as 42 degrees C. That however requires it to be alloyed with some terribly toxic metals, like cadmium (Cd) or thallium (Tl). Pure bismuth can be melted on a stovetop in a basic steel pot. When cooled just enough, given a crystallization nucleus, liquid Bi will form regularly shaped crystals that take over all the different colors due to it's reactivity to atmospheric oxygen and thin film interference of the oxide layer.

8 gram crystal fo bismuth metal.

Besides low melting alloys, bismuth (in it's compounds) is widely used in medicine, especially in treating all kinds of gastrointestinal troubles. Bismuth - chalcogen compounds (Such as Bi2Te3) also make for good thermoelectric materials, utilizing a gradient of temperature to generate a current.

Additionaly, bismuth vanadate is a yellow pigment that is used as a replacement for cadmium sulfide in paints.

Bismuth is an extraoridnary metal and without a doubt will find itself in many more applications in the future. Until then, the colorful crystals make for a great sample of otherwise basic looking element.