How do you say crystal in Japanese?
— 結晶 (けっしょう, kesshō); 結晶

Generic synonyms for crystal in Japanese
stone小石 (こいし, koishi)
Group relationships for crystal in Japanese
watch腕時計 (うでどけい, udedokei); 懐中時計 (かいちゅうとけい, kaichuu-tokei); 時計 (とけい, tokei)
Specialized synonyms for crystal in Japanese
ice氷 (こおり, kōri)
snowflake雪花 (せっか, sekka)
stone小石 (こいし, koishi)