Shattering a gear.

Shatter is a term used to describe the act of destroying a gear piece in order to obtain shards. Players are advised to shatter duplicate pieces of gear, as having multiples does not allow you to use them on multiple characters. Shattering evolved gear will have no negative effect on it, only destroying the duplicates without affecting its evolved capabilities. If you destroy the final piece of an fused gear, you will lose the process you have on it. Evolving and maxing out gear will increase the amounts of shards obtained from shattering further duplicates, making them a large one-time investment that would eventually break even.

Shattering a piece of gear gives you a number of shards dictated by its tier, and the type of shards is fixed depending on the type of gear it is. For unevolved gear, shattering 1-star gear would give 4 shards, 8 shards for 2-star, 32 (plus 1 purple) shards for 3 star. However, for shattering 2-star gear evolved into 3-star, the interface claims you will gain 16 shards (+1 purple), but you only get the normal 8. It also claims shattering 3-star gear evolved into 4-star will grant 40 (+1 purple), while you gain 36 (+1 purple), which is still better than unevolved 3-star's 32, and that all 4-star will shatter for 24 red, blue and green shards each plus 1 purple shard (73 total), while they actually shatter for slightly less and with minor variation between them (~67 shards).

For the Gear Sets, the unevolved versions shatter into 20 blue, 20 green and 1 purple shards for any of the pieces, and 24 blue, 24 green and 1 purple for evolved.

Additionally, it is possible to randomly get a few bonus shards from shattering. It is even possible to gain types of bonus shards the gear normally doesn't yield when shattered.

Stars Unevolved Evolved (+ permanent bonus) Maxed out (+ permanent bonus)
1→2 4 4 (+ 4 ~ 7) 4 (+ 10 ~ 19)
2→3 8 8 (+ 5 ~ 9) 8 (+ ?)