I spend hours looking at all the different glues to fix a stone that broke a while back.
Ended up using this for several reasons.
-Strength
-Waterproof
-Adheres to damp surfaces (Its recommended to wet the stone when gluing)
-Fast curing - less than 30 minutes
-Expands slightly, filling any chips or small gaps.
Attachment 149665
Since then i have used it for a few damaged stones including a Coticule and gluing a wooden base to the back of a couple of jnats, all have turned out well