化學組成, 鍵及結構：(礦物)

Chemical composition, bonding and structure: (Mineral)

原生物：(化石)

Living Specimens: (Fossil)

1.       它具有非常完美的基礎劈理。

2.       它具有單斜晶系。

3.       它呈棕色或黑色呈綠色，風化時甚至呈黃色。

4.       它在劈理面上具有玻璃般的光澤。

5.       當黑雲母分成薄片時，薄片是靈活的，但會在嚴重彎曲時斷裂。

1.       has highly perfect basal cleavage.

2.       It has a monoclinic crystal system

3.       It appears to be greenish to brown or black, and even yellow when weathered.

4.       it has a vitreous luster on the cleavage faces.

5.       .When biotite is separated into thin sheets, the sheets are flexible but will break upon severe bending.

磨碎的雲母用作油漆中的填料和增量劑，作為鑽井泥漿的添加劑，作為橡膠產品中的惰性填料和脫模劑，以及作為瀝青瓦和捲起屋頂上的不粘表面塗層。 它還用於測定火成岩的鉀 – 氬和氬 – 氬方法。

It has a small extent of commercial use.

Ground mica is utilized as a filler and extender in paints, as an additive to drilling muds, as an inert filler and mold-release agent in rubber products, and as a non-stick surface coating on asphalt shingles and rolled roofing. It is additionally utilized in the potassium-argon and argon-argon methods of dating igneous rocks

岩洞, 北卡羅萊納州的羅利帶岩石

Valle del Cervo pluton, Raleigh belt rocks in North Carolina

2. 它曾經是愚人金

2. It has been used as fool’s gold