Here's what I remember:
- Cover: hardcover, turquoise, possible thin yellow embellishment/design in one corner
- Author: Slavic, Jaroslav, maybe?
- Age: old & obscure
- Setting: feudalism
A seneschal to an austere English lord foils the theft of a priceless artifact: a bowl of unusual material crafted by a renowned, though recently deceased, artist. Further investigation into the bowl's properties triggers a space race between a religious cult, Martians (human settlers of Mars), another Lord with a sadistic inclination, and a futuristic policing agency. The investigation traces the final steps of the bowl's maker, from a remote monastery in Mongolia, to the position of court artist at a verdant lunar settlement managed by a boorish Lord with an obsession for low-gravity hunting, to a fantastic, illusionary wild-west Jovian (or Saturnine) cylindrical outpost, and finally to the Jovian (or Saturnine) moons themselves.
The missing artist is still alive, but not for long. And at the end of the rainbow lies the secret to interstellar flight. Mankind gains the ability to spread to other solar systems.