无机非金属材料专业英语-宝石的力学性能

1、Unit 27 Mechanical Properties of Gemstones宝石的力学性能n1、Gemstones may show mechanical characteristics as a result of the application of force, for example gemstones may be damaged, broken and, in some cases, be divided into two or more pieces, etc. n由于施加的力所致，宝石可能会表现出力学特征，如在一些情况下宝石可能被损害、破碎、被分成两片或者多片等。 nM

2、echanical properties involved in gemology are cleavage, parting and fracture, hardness, density.n宝石涉及到力学性能有断裂、分离和破碎、硬度、密度。Cleavage, Parting and Fracture 断裂、分离和破碎断裂、分离和破碎 n2、Cleavage is the ability, possessed by some gemstones, to split along certain well-defined directions leaving more or less flat

3、faces (possibly showing pearly luster), lying parallel to crystal faces, even though crystal faces may not be present in particular specimen.n断裂是一些宝石具备的一种能力，可以沿着清晰的纹路分裂，留下的几乎是平面（可能显示出珍珠光泽），并与晶面平行，即使在一些特殊的样品中晶面了可能不会存在。n3、In certain minerals, this difference in strength is sufficient to allow the crys

4、tal to split, parallel to the densely packed planes, when appropriate force is applied. n在一些材料中，当施加一定的力时，这些强度的差异足可以使晶体分裂，并平行于密排面。 nThis particular type of splitting is called cleavage, is always parallel to an ideal crystal face, and can only occur in a single crystal.n这种特别的分裂类型成为断裂，总是平行于理想晶体面，并且只在单

5、晶体中发生。n4、Because cleavage is a directional characteristic of weak atomic bonding, any direction in a crystal lying parallel to layers of atoms is a potential cleavage direction, although most minerals resist splitting along these various planes.n由于断裂是微弱原子结合的方向性特征，晶体中任何平行于原子层的方向都是潜在的断裂面，虽然大多数矿物质在这些不同

6、位面的分裂会受到限制。 nIt is for this reason that cleavage is a highly diagnostic feature, possessed to a marked degree by only a few gemstones.n正因为如此，断裂是非常特有的特征，仅仅在为数不多的宝石中才会有。n5、When we refer to a gemstone with noticeable cleavage, we need to discuss not only its direction, but also the cleavage quality.n当我

7、们提到一个有明显解理面的宝石时，我们不仅需要讨论它的方向，还要讨论解理面的质量。 nCiting the examples already given, diamond has perfect octahedral cleavage, and graphite has perfect cleavage parallel to the basal plane (of the hexagonal crystal), called basal cleavage. n引用已有的例子，金刚石具有完美的八面体解理面，石墨具有完美的与基面平行的解理面（是六面体晶体），称为基解理。 nOther possib

8、le directions of cleavage include rhombohedral, prismatic, pinacoidal. n其他可能的解理面方向包括：斜方六面体、菱形、地面的。 nCleavage faces may often be recognized by a series of very shallow steps, where the break has occurred along several layers of atoms at the same time.n解理面经常可能经过一系列非常肤浅的程序进行验证，在解理面上同时会沿着原子的几层会发生破裂。n6、T

9、he gemmologist obtains benefit from cleavage because it is an aid to identification, and the cutter obtains some benefit because poor quality areas can be removed easily from rough materials. n宝石学家获益于解理面，因为它可以有助于鉴定，同时切削也获得了一些益处，因为质量差的方面可以轻易的从原材料中去除。 nWhile this feature is of particular importance to

10、 the diamond cutter, there are probably more disadvantages than advantages associated with cleavage. n虽然对金刚石切削来说这种特征尤为重要，但是解理面的缺陷可能远大于优势。 nIt is virtually impossible to polish a gemstone parallel to a cleavage direction.n实际上不可能将宝石抛光至于解理方向平行。n7、Parting is the breaking or splitting along lamellar twin

11、ning planes. n裂理是沿着薄的孪生面的破坏或裂开。 nSometimes the internal structure of a gemstone causes a physical effect similar in appearance to cleavage.n有时宝石的内部结构会引起表面上看起来和解理相似的物理效应。 nHowever, the gemstone breaks or splits along twinning planes. n但是，宝石是沿着孪生面破碎或裂开的。nFor example ruby exists splits at rhombohedral

12、and basal directions.n例如，红宝石在斜方六面体和底部方向存在裂纹。n8、Fracture is the random, non-directional breakage, which occurs in most gemstones as a result of sharp impact, and is often considered to be a typical and identifying feature of glass. n破碎是任意的、无方向性的破坏，存在于大多数宝石，由于突然的作用力所致，经常作为玻璃的典型和标志性特征。 nUp to a point t

13、his is true, but it is also quite typical of amorphous substances in general, and of those crystalline materials that have no pronounced planes of weakness, for example, quartz or beryl.n在一点上这是正确的，但是它也是一般非结晶物质的典型特征，也是没有明显薄弱面的晶体材料的典型特征，如石英和绿宝石。 n9、Several types of fracture are recognized, those norma

14、lly seen by the gemologist being conchoidal or shell-like. n破碎的几种类型已经是公认的，也就是那些通常被宝石学家看作贝克状的或类似贝克的。 nWhen a mineral breaks with curved concavities, then the break is called conchoidal fracture, from the resemblance of the concavity to the valve of a shell.n当一种矿物质破裂成弧形凹面，那么这种破裂称为贝克状破裂，因为破裂凹面相似于壳辨。n10

15、、The fibrous, tough structure of nephrite jade produces another kind of fracture - hackly. n纤维状、坚硬的软绿玉结构产生另外一种类型的破碎-锯齿状的。nThis refers to the uneven, and often jagged, break that occurs when this material is broken.n当这种材料破裂后，就会产生不规则的，并且经常是边缘粗糙的裂纹。n11、Other terms are used as earthy, splintery signific

16、ance for the in mineralogy to describe fractures such and uneven, but these has little significance for the gemologist.n其它的条件也被应用于描述这样的裂纹和不规则，如矿物学的泥土的、破裂意义，但是这些对宝石学家意义不大。Hardness 硬度硬度n12、Hardness is the ability of gem to withstand abrasion, and is one of the prime qualities of a gem material. n硬度是宝石

17、的耐磨能力，是宝石材料的主要质量指标之一。 nThe scale of hardness, which is used universally for gemology and mineralogy, is comparative one.n硬度等级是一个相对等级，广泛的用于宝石学和矿物学。n13、The German mineralogist, Friedrich Mohs produced practical scheme for hardness assessment in 1822. n德国的矿物学家Friedrich Mohs 在1822年制定了硬度评价的实用方案。 n After

18、a number of selection trails, he brought together ten easily obtained minerals, which could be obtained in a high degree purity, and listed them in order of ability to withstand scratching by other members of the group. n经过大量筛选，他把十种容易获得的矿物质放在一起，这些矿物质可以在高纯度下获得。团队的其他成员将这些矿物质依据他们的耐磨能力大小的顺序排列。 nThis res

19、ulted in which is now known as Mohs Scale of Hardness. n以下就是这个实验的结果，也就是现在所为人知的莫氏硬度指标。nThe scale in increasing order of resistance to abrasion is:nTalc 1 gypsum 2 calcite 3 fluorite 4 appetite 5 orthoclase 6 quartz 7 topaz 8 corundum 9 diamond 10n14、 It is important to note that this is only an order

20、 of hardness and that the difference in hardness between any two adjacent members of the scale is not an indication that a uniform difference of hardness exists between other pairs of members. n重要的是应该注意这不仅仅是硬度的顺序排列，并且指标中两相邻成员之间的硬度差异并不表示：其它成员对之间存在一个统一的差异。 nBut the comparable hardness of some other co

21、mmon substances would be noted, for example finger nail (2.5), window glass (5-5.5), steel knife blade (5.5-6) and steel file (6.5-7).n但是某些其它常见物质的相对硬度应该引起注意，例如：指甲2.5，窗玻璃5-5.5，钢制刀片5.5-6，钢锉6.5-7Density and Specific Gravity 密度和比重密度和比重n15、The carbon atoms that unite to form either graphite or diamond, d

22、o so in different ways, not only producing difference in hardness and cleavage, as described in the earlier section, but also differences in their weight/volume ratios, which are termed as density.n碳原子以不同的方式形成石墨或者金刚石，不仅仅造成如前所述的了两者的硬度和解理的差异，也造成了体积/重量比率的不同，也就是密度。n16、The density of every substance, including all gemstones, is determined by the arrangement of its constituent atoms. n每一种物质的密度，包括所有的宝石，是由组成原子的排列决定的。nDensity is measured by the number of units of mass contained in 1 unit volume.n每一种物质的密度，包括所有的宝石