By only one rigid string, transformable by real mechanical mutual collision, seems the real universal building block for Matter, Dark Matter and Dark Energy.
see:
"Primordial Black Holes and Dual Herbig Haro Effects for Star-Galaxy Formation"
https://vixra.org/pdf/2101.0158v1.pdf
Tadpole Comet mini black holes also former S-Nova expelled starspot black holes, with propelling plasma tails searching for a partner to form a Herbig Haro system for a smaller ( Dark) star formation in between.
Mini Black Holes are so called interference black holes expelled by a star and later coming back as comet crashed on the star forming a starspot.