The Diamont were an ancient silicon-based species that looked like rocks infused with diamonds, hence the name. For unknown reasons they went extinct, and the only remaining Diamont is Spire, a bounty hunter who appears in Metroid Prime Hunters. In fact, the reason that Spire seeks the "Ultimate Power" is because he wishes to learn about the fate of the Diamont species. Diamonts have the ability to curl up in big ball. This allows a quick escape or another way to run over their enemies.
Spire appears to be based on an enemy from the cancelled Nintendo GameCube game, Raven Blade, which can be seen in a trailer in a similar setting to Spire's intro video. This game, which was dropped to free up resources for Metroid Prime, was designed by Retro Studios, who also did the Hunters' designs according to interviews. The sudden disappearance of the Diamonts may be a reference to the title as well. In one scene of the trailer for Raven Blade, the creature, who is larger and more simple in design, is shown to lob a ball of lava towards the screen much like Spire's Magmaul.
The name is more than likely derived from diamonds, the hardest natural material known, where hardness is defined as resistance to scratching. While Diamonts are silicon-based, diamonds are carbon-based like life on Earth, and the second most stable form of carbon (after graphite). The ending, "mont", is a French word for "mount" or "mountain".
|Sentient Species in the Metroid Series|
|Human | Space Pirate | Craftsmen | Kriken | Luminoth|
|Reptilicus | Diamont | Elysian | Ing|
|Alimbic | Chozo | N'kren | Phrygisian | Vhozon | Ylla | Jovian |
"Elfin" | "Simian" | "Ceratopsid" | "Space Dragon"