Effects of magical artifacts on non-unicorns

[Pastel 7,630]

For an earth pony...well, I would imagine Fluttershy in Power Ponies...only more angry.

They would get stronger, faster and more resistant.

[Fractured 2,684]

Alicorn magic looks to be a little different from unicorn magic; it's arcane, and its only be used for specific purposes, like raising the sun and moon. Alicorns are also able to utilize unicorn magic,however, which is where the magic blasts and teleportation come from.
The Alicorn Amulet amped Trixie's powers to frightening levels, but it didn't increase her power of illsuions, which is her special talent. It also didn't noticably increase her strength. It's more likely that it boosts the magical potential of any one of the three pony races(pegasi get faster, earth ponies...stronger?), like hypercharging a battery. Sombra himself had enough magic to overthrow Mi Amore and enslave the Crystal Empire, and it took two alicorns to defeat him.