noun
plant opal; opal phytolith
Technical term in botany and soil science for microscopic silica bodies formed in plant cells.
土壌中のプラントオパールを分析すると、過去の植生がわかる。
Analyzing plant opals in the soil reveals past vegetation.
Variant with interpunct; less common but still seen.
Loanword from English 'plant opal'.