Sandstone veins only have about 50 hits before depleted.
Initial Review: There is a mod to fix this but it is uncompleted and it could do more harm than good. Since this won't be a frequent issue, Volcano can increase the vein with a wand until we find a better alternative or fix. Reported by Edarise.
https://forum.wurmonline.com/index.php?/topic/153821-caveresourcefix-fix-your-cave-maps-that-have-resource-counts-set-to-~50-for-non-vein-tiles/