Gems is a Life-like cellular automaton in which dead cells are born if they have precisely three, four, five or seven live neighbors, and in which live cells will survive if they have precisely four, five, six or eight live neighbors. Small random initial configurations in Gems tend to turn into high-period oscillators (the "gems" the rule is named after); larger random initial configurations explode slowly.
No still lives exist in Gems, and no odd period oscillators have been found in Gems.
Gems has a single known spaceship moving orthogonally at a speed of c/5648, David Eppstein's glider 13047. It held the title of "slowest elementary spaceship known across all isotopic rules" until it was surpassed by a c/5953 spaceship in the rule B2-an3acqry4cnw5-cj6cei78/S1c2n3-nqy4acknqtw5-ijkr6ei78.
|Glider 13047 (Catagolue: here)|
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RLE: here Plaintext: here