A single-player deduction puzzle of beams, gems and hidden diamonds
Orapa Mine is a single-player deduction puzzle in the tradition of Black Box and Mastermind, played with light instead of pegs. Gems lie hidden beneath a cover on a grid. You cannot see them — but you can fire beams across the grid and watch where they come out, and what colour they have become on the way.
Gems are hidden under the cover. Around the edge of the grid sit numbered and lettered buttons; press one to fire a beam into the mine from that point.
A beam travels in a straight line until it hits a gem. Each type of gem bends or absorbs the beam differently depending on its shape and its rotation, so the beam may leave the grid somewhere you did not expect — or never leave at all.
When a beam finally exits, note two things: where it came out, and what colour it is. The colour records which gem types the beam passed through on its way, mixing as it goes. A beam that is absorbed outright tells you something too — you have found a blackbody.
One beam is rarely conclusive. Two beams crossing the same region, entering from different edges, is how you pin a gem down.
Your goal is to deduce the position and rotation of every gem from the beam paths alone. Drag the gem pieces onto the grid to record your guesses, then press Submit Solution to check them.
Rotation matters as much as position: the same gem turned a quarter-turn sends a beam somewhere else entirely, so a solution that has every gem in the right square can still be wrong.
A single-player logic and deduction puzzle. You fire beams into a grid of hidden gems and work out where they are from where the beams exit and what colour they have become — the same shape of problem as Black Box or Mastermind.
Deduce the position and rotation of every hidden gem, place your guesses on the grid using the gem pieces, and submit your solution.
No. It rewards careful reasoning rather than calculation — the useful skill is crossing two beams over the same area and comparing what came back.