Neodymium is not particularly abundant in the Earth's crust. It's considered a rare earth element (REE), meaning it's relatively uncommon compared to other elements.

Here's a breakdown:

* Crustal Abundance: Neodymium's abundance in the Earth's crust is estimated to be around 28 ppm (parts per million). This makes it the 25th most abundant element in the crust, after strontium but before thorium.

* Comparison: To put this into perspective, elements like oxygen (46.6%) and silicon (27.7%) are significantly more abundant. Even more common metals like iron (5.0%) and aluminum (8.1%) are far more prevalent than neodymium.

* Rarity: While not as rare as some other REEs (like lutetium), neodymium is still considered relatively rare. Its limited abundance contributes to its relatively high cost.

However, it's important to note:

* Concentrations: Despite its low overall abundance, neodymium can be found in concentrated deposits, particularly in ion-adsorption clays and carbonatites.

* Demand: Neodymium's demand has surged in recent years due to its use in permanent magnets, which are essential components in many modern technologies, including wind turbines, electric vehicles, and smartphones.

Therefore, while neodymium is relatively rare in the Earth's crust, its concentrated deposits and rising demand make it a valuable and sought-after element.