Rare collector coins and expensive nitrogen-based fullerenes

Certain rare two-euro coins hold significant value for collectors due to limited editions or manufacturing errors. A notable example is the 2007 Monaco commemorative coin featuring Princess Grace Kelly, which was issued in only 20,001 copies and can be valued at approximately 3,100 euros. Other valuable items include coins with manufacturing defects, such as the ‘egg in eye’ error where the central part is misaligned, potentially worth 100 euros, or coins with misaligned sides or incorrect metal plates.

In the realm of advanced materials, nitrogen atom-based endohedral fullerenes have been identified as one of the most expensive substances on Earth. Due to the extreme complexity of their production, the material can reach a value of approximately 126 million euros per gram. Developed by Designer Carbon Materials, these molecules consist of nitrogen atoms trapped within a cage of 60 carbon atoms. This unique structure offers physical and electronic properties that could revolutionize technology, including advancements in GPS systems, precision navigation, and the development of smaller, more efficient electronic devices.