>>52581966Sun and Moon Stones represent the sun/day and moon/night. The Shiny (JP: Light) and Dusk (JP: Dark) stones are light and darkness more in terms of benevolence/light magic and malevolence/dark magic.
The Dawn Stone was a translation goof, it has nothing to do with Light in Japanese. It’s called the Awakening Stone there.
Let’s look at what each stone evolves.
For the Fire, Water, Leaf, Thunder, and Ice Stones, it’s kind of obvious. It makes Pokémon of the associated type evolve, usually becoming “more associated” with the stone’s element. There’s also Eevee (all of these stones), Crabrawler (Ice Stone as of Gen 9), and Capsakid where using these stones add their stone’s type to a previously unassociated Pokémon.
The Moon Stone evolves Nidorina/rino and Jigglypuff because they’re rabbit-like and rabbits have a large moon association in Eastern Asia. Clefairy is tied to the Moon through its fairy inspiration and its extraterrestrial nature. Munna is because the moon comes out at night and that’s when dreams are seen as happening. Skitty is kind of the odd one out, but cats are nocturnal and have witchcraft associations which both tie to the moon. The Moon Stone pretty much just evolves creatures that have connotations with the Moon, and pretty much none of these connotations directly have darkness as the malevolent or magical source. At best it’s tangential.
The Sun Stone is even more obvious. Besides Helioptile, everything it evolves (Gloom, Sunkern, Petilil, and Cottonee) is a plant that’s getting bigger because that’s what sunlight does to plants. Helioptile is a lizard that combines the real sun basking behaviours with solar power, so that’s also obvious. Sun Stone isn’t “light” in a symbolic sense, it’s “sunlight” as a real, observable aspect of nature.
Compared to this, Shiny Stone evos are all “good” and “pure”, and Dusk Stone evos are all “malevolent” and “shadowy”.