作者对产自云南马关-麻粟坡矿带、广西钟山八步矿区的黑色电气石进行了矿物组成及化学成分的分析测试。
It shows that there are apparent differences in black tourmalines mineral components and chemical elements from their different producing mines.
自然界产出的电气石品种很多，大部分粉末是黑色或灰色的，在一些需要色泽要求的领域应用受到较大的影响。
Touramaline has many varieties in the nature, and a majority of powder of them is black or cinerous, so their application in the fields where need colour requirements is affected.
自然界产出的电气石品种很多，大部分粉末是黑色或灰色的，在一些需要色泽要求的领域应用受到较大的影响。
Touramaline has many varieties in the nature, and a majority of powder of them is black or cinerous, so their application in the fields where need colour requirements is affected.
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