Combining 10 of these gives you a RANDOM item with an item level that is comparative to your current item level.
It would have been nice since it is a RANDOM item, the pool of Jewelry items (neck, ring, trinket) would have been reduced to only include items that use your current Artifact weapon tree is configured to use. This would be no different to when you select your loot spec in Retail.
Right now I am sitting at a 1-10 chance I could use the jewelry when I get one.
In Legion the big gripe was the randomness of Legendary items, I guess they want to keep that level of frustration with jewelry upgrades in this remix.