What is mountain sherd used for?

The wiki claims turning it into a captivating treasure isn’t worthwhile Mountain-sherd - Official Sunless Sea Wiki

The Interactions table it provides as evidence, is largely full of ways to GAIN a mountain sherd. as far as i can see, very few ways to actually use it, mostly the father’s bones ambition (which im not doing) and the carnelian exile’s questline. it’s not clear on how many that requires, can anyone specify?

i don’t understand what you mean by this.
can you confirm that it’s only used on two occasions in total, and hence that only 2 are ever needed for quests?

Ok, i’ve updated the wiki page to be more helpful Mountain-sherd - Official Sunless Sea Wiki

Wasn’t the mountain shard what you use to resummon Mt Nomad?