zum Steinerweichen

Etymology
+ gerund of. lit. 'to soften a stone, for softening a stone', probably alluding to.

Adjective

 * 1) heartbreaking, heartrending, breathtaking that elicits great positive or negative sympathy

Adverb

 * 1) heartbreakingly, breathtakingly

Usage notes
Apparently found in the colloquial in the areas of Prussia and Hannover in the 18th to 19th century, now not even found in journalistic registers but restricted to literary use and not likely familiar even to the educated.