石膏和巴黎石膏之间的差异

Thekey differencebetween gypsum and plaster of Paris is that the石膏含有硫酸钙二水合物，而巴黎的石膏含有硫酸钙半水合物。

石膏是天然发生的mineral. Plaster of Paris and gypsum both contain calcium sulfate’s hydrate form, but their water content in a molecule differs from each other. Therefore, this is the main difference between gypsum and plaster of Paris.

内容

1.Overview and Key Difference
2.什么是石膏
3.What is Plaster of Paris
4.并排比较 - 表格形式的石膏与巴黎的石膏
5.概括

什么是石膏?

Gypsum is a hydrated calcium sulfate mineral with the molecular formula CaSO₄·2H₂O.这是最常见的硫酸盐矿物质。它是一种形成岩石的矿物，可以长到非常大的尺寸。通常，晶体的颜色是白色或无色的，但也可以具有其他颜色的阴影，例如灰色，红色或黄色。晶体也可以作为透明或半透明。石膏是一种柔软的晶体，我们甚至可以用指甲刮擦它。此外，它是一种柔性材料，其热导率较低。石膏略微溶于水，当我们加热水时，水会蒸发并可以再次达到甲基氢固态。石膏存在于世界各地的许多地方（英国，俄罗斯，加拿大，非洲，亚洲，美国和欧洲）。但是，在美国的科罗拉多州和墨西哥，石膏很丰富。

Formation and Types

该材料的主要构造途径来自海水的沉淀。在形成矿物质时，水或不需要的材料会捕获晶体内的原因，这是不同颜色晶体的原因。此外，石膏有三种类型。它们如下：

• Selenite
• 雪花石膏
• 纤维石膏

Seleniteis crystalline in nature and appears transparent or translucent.雪花石膏生长成大量的矿物床。它具有浅色或浅色（由于杂质）。另一方面，缎晶石is fibrous or silky in nature. We can use this material for making plaster of Paris, some cement, fertilizer (ammonium sulfate fertilizer) and as an ornamental stone. Also, gypsum is useful as manure, and it is a good source of sulfur. Moreover, it has the capability of becoming plastic like when we heat it up to 175^oC. This nature of Gypsum is important in producing plaster of Paris. If the content of CaSO₄·2H₂o在石膏中很高，它在生产肥料，巴黎和水泥的膏药中非常有效。因此，对纯石膏的需求很高，至少有80％的Caso₄·2H₂o内容。

什么是巴黎石膏？

We can produce plaster of Paris from gypsum. People used this material from the ancient times. Plaster of Paris got its name because earlier people living in areas near Paris used this material widely, to make plaster and cement. They also used it to do ornamental work on ceilings and cornices. Plaster of Paris contains the calcium sulfate hemihydrates (CaSO₄·0.5H₂o）。

我们可以通过加热含有硫酸钙二水合物的石膏来制备这种化合物（CASO₄·2H₂O) to a temperature of about 150^oC (120-180^oC）。加热时我们应该添加某些添加剂。巴黎石膏是一种细的白色粉末。当它变得水分时，我们可以使用它来塑造东西，如果我们允许它干燥，它会变硬并保留在干燥前设置的任何形状。

石膏和巴黎石膏有什么区别？

石膏是天然发生的soft sulfate mineral whereas plaster of Paris is a building material that we use for protective or decorative coating purposes. Both these materials contain calcium sulfate as the major constituent. Although both gypsum and plaster of Paris contain calcium sulfate as the major component, they have differently hydrated calcium sulfate. Hence the two materials become different from each other. Therefore, the key difference between gypsum and plaster of Paris is that Gypsum contains calcium sulfate dihydrate whereas plaster of Paris contains calcium sulfate hemihydrates. Moreover, another difference between gypsum and plaster of Paris is that we can mould plaster of Paris into different shapes when we moisten it while we cannot do this for gypsum.

概括– Gypsum vs Plaster of Paris

巴黎石膏的生产主要来自石膏。但是，石膏和巴黎石膏之间几乎没有差异。其中，石膏和巴黎石膏之间的关键区别在于，石膏含有硫酸钙二氢酸钙，而巴黎的石膏含有硫酸钙半水合物。

Reference:

1.“石膏。”。Wikipedia，Wikimedia基金会，2018年10月10日。Available here
2. “Plaster.” Wikipedia, Wikimedia Foundation, 27 Sept. 2018.Available here

Image Courtesy:

1.“ GIPS - Lubin，波兰” Elade53 - 自己的作品，（公共领域）通过Commons Wikimedia
2.”Fontainebleau escalier roi5″By No machine-readable author provided. (Public Domain) viaCommons Wikimedia