This is so much fun......
#1. I've had better success if I wet the 'filler' material....sort of pre-felting that portion....the whole piece holds together much better that way.
#2. After wetting the filler, it's placed on roving strands which are then rolled around the wet mass. I've increased the amount of roving I used originally....that has helped a lot too.
#3. It may not show too much in the photo...but I've taken to throwing the wet/soapy rock onto my rather rough cutting mat.....that sped up the felting process. Though the soapy water spatters....
Once they are felted.....rinse thoroughly and squeeze as much water out as possible...shaping as you go....dry on towel.
I'm making better progress to with the veins....
Ta-da......I'll make more....but you get the idea..... This also calls for a shopping trip to find a more attractive display bowl.