Thick clouds darkened the sky before the rain fell.

From northern skies a cloud approaches, aloft upon the winds of change.

乘着易迁之风，一团黑云自北方的天际压来。

Dark clouds bearing down on the city threaten to overwhelm it.

黑云压城城欲摧。

REE distribution in the first phase intrusive rock descends in an order of pyroxenite to biotite pyroxenite to apatite rock.

第一期侵入岩较其它期次侵入岩REE含量高，按辉石岩黑云母辉石岩磷灰石岩的顺序增加。

Optics and micro-shape characters in the process of biotite transforming to chlorite

黑云母向绿泥石转化过程中微观形态及光性特征

He that sends the clouds can as easily clear the skies.

祂能将黑云密布天空，祂也能很容易地使天气清朗。

Look at the heavy clouds! It's going to rain.

看那黑云！天要下雨了。

Look at those dark clouds! it's got to rain today.

你看这黑云，今天准得下雨。

The results show significant differences in oxygen isotope composition between biotite gneiss and granitic gneiss.

结果表明，这两种片麻岩在氧同位素组成上存在显著差别：黑云母片麻岩与共生的榴辉岩δ18O值呈同步变化，全岩δ18O值从－4.7‰变化至＋10.3‰；

Behind them black clouds piled one atop another against a blood-red sky.

在他们身后是血红天空上的一团相互堆叠着的黑云。

Is but a cloud, and like a shady grove.

只是一块黑云，像一片浓郁的小树林。

Biotite ( hornblende) two-feldspar gneiss and ( 5) Fault br.

黑云（角闪）二长片麻岩和（5）碎裂岩等。

The nature of mineralogy, petrology and geochemistry also provides reliable information to prove that primitive tuffaceous sedimentary rock underwent "soaking effect" in a kind of brine and formed scapolite biotite rock.

矿物学、岩石学及地球化学特征也为其原凝灰质沉积岩经过热卤水浸泡效应（soaking effect）形成方柱黑云岩类的成因提供了可靠信息。

In the genetic diagram of mica minerals, biotite in the study area mostly falls into the field C, indicating a crustal origin.

在云母类矿物的成因图解显示，研究区内大多数黑云母均位于C区，属壳源。

Can dark clouds hide the hidden from the mighty eye of god?

黑云能否遮掩上帝无处不在的眼？

A heavy dark cloud presaging rain or a storm.

预兆雨或暴风雨的沉重的黑云。

U-Pb isotopic ages of 61 detrital zircon grains from the sillimanite-biotite-quartz schist of the Qinling Group in the North Qinling metamorphic terrane are reported in this paper. Of the 61 zircon grains, 15 were measured by SHRIMP ⅱ, and 46 by LA-ICPMS.

报道了北秦岭地块中秦岭岩群夕线黑云石英片岩61个碎屑锆石测点的207Pb/206Pb年龄测试结果，其中15个测点在SHRIMPⅡ上进行，46个测点来自LA-ICPMS的测定结果。

The second stage is the intrusion of medium to fine-grained biotite-K-feldspar granite.

第二阶段为中细粒黑云母钾长化岗岩。

There is a threat of rain in the dark sky.

黑云密布的天空有下雨的兆头。

Dehydration-melting experiment of the biotite-gneiss, eastern hebei, at 1 GPa pressure

冀东黑云母片麻岩在1GPa压力下脱水熔融实验

The black clouds indicate that it will rain soon.

黑云预示着快要下雨了。