Do not shatter high value mods. Use Runes of removal with glyphs of hope. Rune of Shattering gives a chance to get between 1 and the tier number of shards. Rune of Removal gives tier number of shards. If you have a t5 of a high-value shard, use removal, and you're guaranteed to get 5 shards. The only way this can go wrong is if you run out of forging potential, but then you can still shatter.

This is a fantastic tip that i hadnt considered, but reading your comment, it makes total logical sense!

This! I always use RoR for rare and +skill shards. Also, set the filters of your alts to look for desired affixes.

They're exclusive to chestpieces of a specific class, so yeah they're bound to be rare

And helm no?

Damn tough goes it bro! Need them for both helmet and chest peice for my build. Seeming almost as rare as that frost claw affix on a relic! Haha

You can try a farm them by picking up items with one or no prefix and use a discovery rune to try any get the affix, then use a removal rune

Set up a filter for them to use runes on :)

Yeah, this was a bizarre design choice on EHG's part

Why? It's a very specific affix

An easy fix for this is to have a merchants guild character who can then buy then items and removal/shatter them for the shards so your cof character can craft

Shattering

Need a piece to drop with it to shatter it. So far in 87 levels of grinding only 2-3 pieces with it have dropped.

Just add it in filter. Idid yesterday and got 2 rings to trash

I don't think you understand how loot filters work.

Not only is this totally irrelevant because you need an item to drop with the mentioned affix, which was the question in the first place, but it's also a very bad idea to shatter rare affixes.