There isn't a single, universally accepted term for rare and beautiful elements. However, depending on the specific context, you could use terms like:

For elements that are both rare and visually stunning:

* Precious metals: This term typically refers to gold, silver, and platinum, but could also include others like iridium and rhodium.

* Rare earth elements: These elements, despite their name, are not actually rare in the Earth's crust. However, they are difficult to extract and refine, making them valuable. Some of them have beautiful colors, like the reddish-purple cerium.

* Gemstones: While gemstones aren't elements themselves, they are often made of elements like carbon (diamond), beryllium (emerald), and aluminium (ruby).

* Lustrous elements: This term describes elements that have a shiny or reflective surface. This can include elements like gold, silver, and even some metals like tungsten.

For elements that are rare and have a particular scientific or historical significance:

* Exotic elements: This term is often used to describe elements that are not found naturally on Earth or are very difficult to create.

* Radioactive elements: Some rare and radioactive elements, like polonium and radium, have a captivating history and scientific interest.

Ultimately, the best term to use depends on the specific context and the elements in question.