名詞 mica:

1. any of various minerals consisting of hydrous silicates of aluminum or potassium etc. that crystallize in forms that allow perfect cleavage into very thin leaves; used as dielectrics because of their resistance to electricity
   同義詞：isinglass

mi.ca

n.（名詞）
Any of a group of chemically and physically related aluminum silicate minerals, common in igneous and metamorphic rocks, characteristically splitting into flexible sheets used in insulation and electrical equipment.
云母：化學上和物理上有聯系的鋁硅酸鹽礦物群的總稱，常見于火成巖和變質巖中，以易裂成柔軟的薄片為特征，用于絕緣體及電氣設備中

來源：
Latin [grain] perhaps influenced by Latin mic3re [to flash]
拉丁語 [谷物] 可能受 拉丁語 mic3re的影響 [閃光]

【引伸】
mica.ceous