The player can obtain the Abomasite by defeating Mega Abomasnow in Stage 620 found on Zaffiro Coast.
The Abomasite was also available as a prize during the Mega Abomasnow Competitive Stage. This Competitive Stage ran on the Nintendo 3DS version from February 9 to 16, 2016; May 31 to June 7, 2016, and December 6 to 13, 2016. It ran on the Pokémon Shuffle Mobile from May 31 to June 7, 2016; and December 6 to 13, 2016.
The Abomasite enables the following Mega Evolutions:
An Abomasite appeared in A Real Icebreaker!, worn by Wulfric's Abomasnow. The Frost Tree Pokémon wears its Mega Stone on its chest, revealing it only when it was about to Mega Evolve. Wulfric used it during Ash's rematch against him, in which it battled Greninja.