How heavy are turbofan and turboprop propeller blades?
According to this ATSB Australia Report, the Original Blade Weight of the Trent 800 Blade that failed was 11.6KG. The weight of the blade in grammes is etched into the blade root.
https://www.atsb.gov.au/media/33974/tr200100445_001.pdf Page 9/10.
Fan Blades of the same type all differ (slightly) in weight and are chosen specially to balance the engine when it rotates, or balance weights are added to the blade much like your wheel on your car. This is to avoid vibration.