I often see that diamond and gold blocks are used in different Redstone circuits, why? Have the special properties?
Sounds more like decoration and the demonstration is certainly synonymous in the creative, because you have enough of the stuff ^^
I think for guidance. One could also want to take. But actually they have no special features regarding redstone. In how far is that used? Is this the trigger or is there a line or something?
No, they have no special features and are just used in tutorial or show videos only for better understanding or orientation.
The only blocks that behave differently are glass blocks or Glowstone, these do not pass on a Redstone signal.