There are thousands of different periodic tables in existence. Aside from the usual ones that offer atomic masses and numbers, for a long time we have had those that revealed various periodic trends. In more recent years, some have focused on their time or place of discovery, on cosmic origins of the elements, and even on endangered “species”.
Many academic institutions and a slightly-richer-than-the average-guy by the name of Bill Gates, have placed actual samples of elements in cubicles to create a 3D-version. There are more modest tables filled with beautiful photographs of the elements—in fact, you can even get a 1000 piece jigsaw puzzle version.
(Although it should have had 118 or 1180 pieces to match the number of elements. 🙂 )
I thought of creating one more, a table that focuses on some of the natural sources of the elements—even though I’m sure the idea is far from original. You probably know already that such a table will leave out synthetic ones, about 34 of them. Of course, for most of the remainder, there is more than one natural source. So anyone else who has created such a table will have put together merely one of at least millions of possibilities.
You will notice that whereas a periodic table has mostly metals, the natural source- version consists of mostly minerals, which I find more aesthetically pleasing. A rock is a heterogeneous mixture of minerals, while a mineral is similar to a chemical compound, but it is not as narrowly defined. Its composition can vary within limits; impurities can drastically change the colour of a mineral, and those impurities can sometimes be the only source of the element, as is the case with rhodium and several of the rare earth elements.
The list of elements that can be found in their native, non-bonded state is longer than most of us imagine. It includes four of the five elements in group 15: nitrogen, arsenic, antimony and bismuth; all three mintage elements: copper, silver and gold; iron and nickel in meteorites—in fact native iron can also be found in basalt; five other heavy metals: osmium, rhodium, iridium, palladium and platinum; oxygen, sulfur and, of course, all six noble gases.
For four of the elements, helium, gallium, rubidium and cesium, I included spectra, which is how those elements were discovered. In helium’s case, the scientists were looking at the sun’s outer layers during the eclipse of 1868. Only decades later was helium gas found on earth when it was found to be released from a uranium ore. Soon after, they realized that lots could be extracted from natural gas sources.
If you refer back to the first table I listed, that of the endangered elements, you will notice that helium is one of them. The number of suppliers worldwide is limited. If one of them experiences issues, shortages quickly develop. This leads to a spike in prices for the simplest but most essential of the noble gases. Helium is used as a coolant in MRIs, smartphone-manufacturing and other applications.
It’s just not recycled enough, if at all, as is the case with many of the endangered elements.