While following a quest, I ended in Mzulft where I found the Dwarven Storageroom. Playing as a garbage collector, I cleaned it all, including the Glowing Crystal Shard.
Several hours later, after complete the Dawnguard Questline by killing Lord Harkon, I decided to do the sidequests and then I read the book The Aetherium Wars, however the misc quest Investigate the ruins of Arkngthamz did not trigger.
I searched about and I have seen people with the same problem but they completed, in the way of forge one of the Aetherium equipments, by traveling by their own.
I did the same, but Katria's Ghost was not present in any of the locations a Crystal Shard could be taken and, now in Ruins of Bthalft, without her ghost again, I can't activate the Dwarven Mechanism to access the Aetherium Forge.
More search for possible solutions involving setstage and setquest console commands, I tried then all, with several different quest stages and nothing happen.
Will I stay with this Steam achievement uncompleted?
31 Answer
1 of the 4 Shards is called "Glowing crystal shard" and can be dropped into containers, so its probably in your house or in a vendors inventory.
You can only activate the forge with 4 pieces, so you will have to hunt down the last piece in your house/vendors.