水すい晶しょう婚こん式しき

す

い

しょ

う

こ

ん

し

き

Meanings

1

noun

crystal wedding; 15th wedding anniversary

Refers specifically to the 15th wedding anniversary celebration or the anniversary itself.

water

晶sparkle, clear, crystal

婚marriage

式style, ceremony, rite

銀ぎん婚こん式しき
Refers to the 25th wedding anniversary (silver wedding), while 水晶婚式 is the 15th.
金きん婚こん式しき
Refers to the 50th wedding anniversary (golden wedding), a much later milestone.

Compound of 水晶 (crystal) and 婚式 (wedding ceremony/anniversary), following the Western tradition of naming anniversaries after materials.