Silicates

硅酸盐

The most abundant elements in the Earth's crust are oxygen (46.6%) and silicon (27.7%). Minerals which combine these two elements are called silicates, and combined they are the most abundant minerals on the Earth. The silicates can be organized in terms of their chemical compositions and their crystal structures (indicated by the existance of cleavage planes). They most often contain members of the Big 8 elements. The table below is an example of such organization from Lutgens and Tarbuck.

地球 crust 中最丰富的元素是氧（46.6%）和硅（27.7%）。结合这两种元素的矿物被称为硅酸盐，它们是地球上最丰富的矿物。硅酸盐可以根据其化学组成和晶体结构（由解理面的存在指示）进行分类。它们通常包含大八元素中的成员。下面的表格是从 Lutgens 和 Tarbuck 提取的一个此类分类的例子。

Mineral 矿物		Idealized Formula 理想公式	Cleavage 解理
Olivine 橄榄石		(Mg,Fe)₂SiO₄ (Mg,Fe)₂SiO₄	None None（矿物名）
Pyroxene group (Augite) 辉石类（辉石）		(Mg,Fe)SiO₃ (Mg,Fe)SiO₃	Two planes at right angles 两个互相垂直的平面
Amphibole group (Hornblende) 角闪石类（辉石）		Ca₂(Fe,Mg)₅Si₈O₂₂(OH)₂ Ca₂(Fe,Mg)₅Si₈O₂₂(OH)₂	Two planes at 60° and 120° 两个平面，倾角分别为60°和120°
Micas 云母	Biotite _biote_	K(Mg,Fe)₃AlSi₃O₁₀(OH)₂ K(Mg,Fe)₃AlSi₃O₁₀(OH)₂	One plane 一个平面
	Muscovite 长石	KAl₂(AlSi₃O₁₀)(OH)₂ KAl₂(AlSi₃O₁₀)(OH)₂
Feldspars 长石	Orthoclase 斜长石	KAlSi₃O₈ 钾铝硅酸盐	Two planes at 90° 两个成90°角的平面
	Plagioclase 斜长石	(Ca,Na)AlSi₃O₈ (Ca,Na)AlSi₃O₈
Quartz 石英		SiO₂ SiO₂	None None（矿物名）

Shipman, et al. comment that about 95% of the continental crust rocks are composed of the two types of feldspar or quartz.

Shipman 等人指出，大陆地壳中的约95%的岩石由两种类型的长石或石英组成。