We know a lot of elements which sum up to 118 of them in total but as humans, we are so quick to give credit to a very few including Oxygen, Carbon, Nitrogen, Iron, Calcium, and Hydrogen while leaving the rest like they never existed but this isn't true because there are a lot of elements that we use on a daily basis that we do not give credit to even when they are very useful.
One element that is very uncommon but useful is Praseodymium which has the atomic number 59, and is a Lanthanide sitting on the first row on the lower list of elements on the periodic table. Lanthanides aren't good conductors of electricity but are able to make strong bond with other elements which allows Praseodymium to make heat resistant bonds when it bonds with other metals and it is this heat-resistnce capability that allows it to be used in aircraft engines so as to help the aircraft function well without breaking as a result of extreme tremperature. If you have seen welder glasses, then you have seen something made out of Praseodymium and it resists heat.
Just next to Praseodymium on the periodic table is the element with the atomic number 60 known as Neodynium and it functions similarly to Praseodymium when it comes to heat resistance but it is also used as magnet as its atoms are well aligned which is why when it mixes with iron, it gives a very good magnet. You see lasers in movies and possibly in real life and they are different from light bulb. Lassers appear in different color ranges and uses Yttrium crystals in the form of Yttrium aluminium garnet (YAGs). Normally, Yttrium is heat resistance and will not release any light but when a part of the Yttrium is replaced by similar elements such as Neodynium, it begin to produce light. These lasers are what doctors use for laser surgeries in the hospital including in eye surgeries.
Let's discuss Osmium which is the densiest element on the periodic table. With electrons that orbits close to the its nucleus, its atom compacts together than majority of the elements that we know. One time Osmium was in high use was during the time of record player needles and this was because they didn't wearout like other needles did also, osmium is found in the tip of fountain pen and this is because of their ability to rub without wearing down. While you might have not heard of this elements because they aren't as popular as your everyday known elements, we cannot deny their importance and presence in our world.
Reference
https://www.rsc.org/periodic-table/element/59/praseodymium
https://www.compoundchem.com/2019/08/16/iypt059-praseodymium/
https://chem.libretexts.org/Bookshelves/Inorganic_Chemistry
https://www.rsc.org/periodic-table/element/60/neodymium
https://pmc.ncbi.nlm.nih.gov/articles/PMC6323575/
https://www.magnetexpert.com/blog/common-applications-of-neodymium-magnets/
https://www.sciencedirect.com/topics/earth-and-planetary-sciences/yttrium-aluminum-garnet
https://www.rsc.org/periodic-table/element/76/osmium