• 在晶体形成过程中发生了什么使它成为一种或另一种颜色?<李> / < / ul >

Chemicals
不同的化学物质可以产生不同的颜色。例如，紫水晶的晶体结构中含有微量的铁，因此呈紫色。铁也能使晶体呈现黄色。

[编辑:查看Gimelist的回答，获得更详细和丰富多彩的解释]

生长缺陷
有些颜色，如烟状石英，来自生长缺陷。这些缺陷改变了晶体反射光的方式，从而改变了颜色的外观。

<强>光
观察晶体时看到的部分颜色是浅色。当光进入晶体时，它的光谱被分解，一部分被吸收，另一部分被反射。这将改变晶体的表观颜色

你可以把化学着色分为三个主要部分(可能还有更多，但这些是重要的部分):

<强>夹杂物

一个大的固体晶体可以含有其他固体矿物的微小夹杂物。通常这些夹杂物太小，肉眼无法单独观察到。显微方法，无论是光学或电子，通常需要正确识别夹杂物。尽管如此，当在宏观尺度上观察晶体时，夹杂物给矿物赋予了它们特有的颜色。

这里有一个很好的例子:

^{(图。Anenburg的4< em>et al. 2014)}

你可以看到底部的蓝色天青石(硫酸锶)，顶部的白色方解石(碳酸钙)。它们的界面分别是红色和橙红色。原因是存在微小的微米大小的氧化铁夹杂物(，即。< / em >生锈)。注意，氧化铁是不同的矿物。 hematite, goethite, etc.

Mineral inclusions can sometimes cause even more spectacular effects, such as asterism: ^{(source: Charles Tilford)}

In this case, the cause are tiny inclusions of rutile (titanium oxide).

Crystal field theory (allochromatism)

The crystal field theory explains, among other things, what happens to light as it encounters metals in different structural configurations inside a crystal. Keeping the complicated terminology at minimum (energy level splitting yay!), what basically happens is that different metal cations (positively charged atoms) in a crystalline structure absorb different wavelengths of light. The identity of the metal is not the only important thing: a paramount factor is the number of oxygen atoms that surround the metal atoms and their shape (be it a tetrahedron, octahedron, etc.) These metals are not part of of the formal chemical composition of the mineral. Instead, they replace other atoms in the mineral by very little amounts. For example, ruby is a mineral composed of aluminum oxide. If you take just a bit of this aluminum and replace it with chromium (less than 1% is enough), it becomes vivid red. Note that in contrast to inclusions, we are talking about different metals in the same mineral, and not inclusions of different minerals.

A digestible explanation with some nice photographs and applets can be found here: http://www.chm.davidson.edu/vce/coordchem/cft.html

Idiochromatism

This is the case where the color of the mineral is not dictated by trace amounts of metals in an otherwise colorless mineral (see the ruby example above), but rather by the major chemical constituents of the mineral. A great example is copper, which gives strong green colors to some minerals that contain it (e.g. malachite):

^{(Rob Lavinsky, iRocks.com – CC-BY-SA-3.0 [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons)}

Or the red color of cinnabar, given by mercury:

^{(Rob Lavinsky, iRocks.com – CC-BY-SA-3.0 [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons)}