Calcite crystals are often Employed in optical tools, and even the graphite in pencil lead are sheets of crystals that essentially break apart layer by layer to jot down. Silica can form silicate crystals which can be the basis for quartz, mica, olivine, and a number of other crystals and minerals.
无色水晶以晶莹美丽、洁净透明着称。衡量无色水晶主要看它的纯度，越纯、越透明越好。干净的、无瑕疵的、杂质少的价值就高。无色的水晶如果很脏，就没有利用价值。
一般而言，紫晶和黄晶是水晶中价值较高的品种。两者进一步的分级是据其颜色的深浅，颜色较深的为A级，稍浅的为B级。一般颜色较深的价格高，但要以不深暗为标准。颜色包括两种，一种是水晶本身的颜色，另一种是内部包裹体的颜色。水晶本身的颜色要艳丽、纯正，分布要均匀，不能太深或太浅，如澳州玉、蓝玉髓、紫晶、黄水晶，其价格就高。无色的水晶内含包裹体的颜色艳丽，其价格也高，如钛晶、绿幽灵、红兔毛。紫水晶一般以稍有云状物、颜色深紫、晶体通透的为上品。
Incorporate to phrase checklist Add to word list C2 [ U ] clear glass of very top quality, usually with its surface Slash into delicate designs
根据美国已经了解的情况，统计局的专家和其他人口统计学家在他们的视野中提供了一个不可抗拒的水晶球。
当二氧化硅结晶完美时就是水晶；结晶不完美的就是石英：二氧化硅胶化脱水后就是玛瑙；二氧化硅含水的胶体凝固后就成为蛋白石；二氧化硅晶粒小于几微米时，就组成玉髓、燧石、次生石英岩。
⑩、雷射内雕：以计算机辅助激光设备在水晶对象中进行三维图案的成型，艺术效果好，可以任意表达各类图案，图形，达到逼真效果
如果水晶内部杂质中有传说中人物的造型，如佛、星座、生肖等价值可能要高于同等颜色和净度的水晶。
One of the binary crystals, the best structures to visualize are those with equal quantities of the two types of atoms. The composition of sodium chloride is predicated on the dice. To build the lattice, the sodium and chlorine atoms are placed on alternate corners of a cube, and the structure is recurring (Determine 3B).
看文化：水晶里面的包裹体象形，能与文化、宗教及历史有所牵连的话，价格往往会比水晶本身的价值高出几倍甚至几百倍。
From the Cambridge English Corpus We are saying the chain topology from the higher w location acts because the proverbial ' scratch-on-theglass ' essential during the natural and organic chemistry laboratory for making crystals. In the Cambridge English Corpus Regular-stress and temperature molecular-dynamics simulations of crystals from the lecithin fragments - glycerylphosphorylcholine and get more info dilauroylglycerol. Within the Cambridge English Corpus In combination with these, dust particles are actually noticed in minimal-temperature plasmas, like those Utilized in plasma processing and plasma crystals. In the Cambridge English Corpus The ultimate Element of the ebook concentrates on peculiarities of strongly coupled dusty plasmas, such as the development of dust crystals and involved desirable forces. From the Cambridge English Corpus Finish characterization of injury threshold in titanium doped sapphire crystals with nanosecond, picosecond, and femtosecond laser pulses. From the Cambridge English Corpus Unbroken crystals are euhedral; rounded, or even more irregular, Most important morphologies weren't observed. Through the Cambridge English Corpus See all examples of crystal These examples are from corpora and from resources on the web. Any opinions while in the illustrations do not stand for the impression on the Cambridge Dictionary editors or of Cambridge University Push or its licensors.
国家还并未给天然水晶提供一个等级划分的具体标准，水晶品种繁杂，每一品种都有他不同的评判标准。
水玉：中国最古老的称法叫水玉，意谓似水之玉，又说是 �?千年之冰所�?�?。唐代诗人温庭筠《题李处士幽居》写道：�?水玉簪头白角巾，瑶琴寂历拂轻�?”。水玉一词最早频繁出于《山海经》：�?又东三百里，日堂庭之�?…�?多水�?”；�?丹山出焉，东南流注于洛水，其中多水玉 ”；�?逐水出焉，北流注于渭，其中多水玉 ”。司马相如《上林赋》曰�?�?水玉磊河 �?。水晶得名水玉，古人是看�?�?其莹如水，其坚如�?�?的质地。
21You all know the way any time you take a crystal prism and go a beam of daylight by way of it, you receive a spectrum, which appears like a constant band of rainbow shades.