coral, centimeter
珊 centers on coral, the hard branching material from the sea. The centimeter sense is a modern phonetic borrowing unrelated to the original meaning.
珊 combines 王 (jewel) with 册, which likely contributes the sound. Together they express coral as a jewel-like marine material.
The left side 王 (jewel) and right side 册 (a bundle of bamboo slips) together suggest a precious, branching structure like coral: a jewel of the sea.
For サン, imagine coral glowing under the sun: sun -> サン, and the coral shines like a jewel.
coral
tabulate coral (extinct coral of the order Tabulata)
tabulate corals (extinct corals of the order Tabulata)
coral wedding (anniversary); 35th wedding anniversary
sweet viburnum (Viburnum odoratissimum)
Cornus alba
Coral Sea
corallite
coral (color); light red
Brazilian plume flower (Justicia carnea); Brazilian plume
coral snake
organ-pipe coral
brain coral
red coral (Corallium japonicum)
yellow clown goby (Gobiodon okinawae)