1.珍珠是怎么形成的英语作文
The birth of a pearl is truly a miraculous event. Unlike gemstones or precious metals that must be mined from the earth, pearls are grown by live oysters far below the surface of the sea. Gemstones must be cut and polished to bring out their beauty. But pearls need no such treatment to reveal their loveliness. They are born from oysters complete — with a shimmering iridescence, lustre and soft inner glow unlike any other gem on earth.
A natural pearl begins its life as a foreign object, such as a parasite or piece of shell that accidentally lodges itself in an oyster’s soft inner body where it cannot be expelled. To ease this irritant, the oyster’s body takes defensive action. The oyster begins to secrete a smooth, hard crystalline substance around the irritant in order to protect itself. This substance is called “nacre.” As long as the irritant remains within its body, the oyster will continue to secrete nacre around it, layer upon layer. Over time, the irritant will be completely encased by the silky crystalline coatings. And the result, ultimately, is the lovely and lustrous gem called a pearl.
How something so wondrous emerges from an oyster’s way of protecting itself is one of nature’s loveliest surprises. For the nacre is not just a soothing substance. It is composed of microscopic crystals of calcium carbonate, aligned perfectly with one another, so that light passing along the axis of one crystal is reflected and refracted by another to produce a rainbow of light and color.
Cultured pearls share the same properties as natural pearls. Oysters form cultured pearls in an almost identical fashion. The only difference is a person carefully implants the irritant in the oyster, rather than leaving it to chance. We then step aside and let nature create its miracle.
2.谁有关于宝石的英语文章
这里有宝石的英文名字而已： Agate 玛瑙 Aguamarine 海蓝宝石 Alexandrite 亚历山大变色石 Alexandrite Cat’s eye 亚历山大变色猫眼 Amber 琥珀 Amethyst 紫水晶 Andradite 钙铁榴石 Apatite 磷灰石 Apophyllite 鱼眼石 Augite 普通辉石 Axinite 斧石 Banded Agate 条纹玛瑙 Barite 重晶石 Benitoite 蓝锥矿 Beryl 绿柱石 Celesite 天青石 Cessiterite 锡石 Chiastolite 空晶石 Chrysoberyl Cat’s eye 金绿宝石猫眼 Citrine 黄水晶 Coral 珊瑚 Chrysoberyl 金绿宝石 Danburite 赛黄晶 Demantoid 翠榴石 Diamond 钻石 Diopside 透辉石 Dioptase 透视石 Emerald xxx Enstatite 顽火辉石 Euclase 蓝柱石 Fluorite 萤石 Garnet 石榴石 Green Quartz 绿水晶 Grossularite 钙铝榴石 Hawk’s eye 鹰眼石 Hydrogrossular 水钙铝榴石 Iolite 菫青石 Jadeite 硬玉、辉玉、翡翠 Kunzite 孔赛石 Kyanite 蓝晶石 Lapis Lazuli 青金石 Lazulite 天蓝石 Malachite 孔雀石 Marble 大理石 Moldavite 摩达曼托石、绿曜岩、暗绿玻璃 Natural Glass 天然玻璃 Obsidian 黑曜岩 Oligoclase 奥长石 Opal 蛋白石 Black Opal 黑蛋白石 Fire Opal 火蛋白石 Orthoclase 正长石 Pearl 珍珠 Mother of Pearl 贝壳 Peridot 橄榄石 Prehnite 葡萄石 Rose Quartz 粉晶 Ruby 红宝石 Sapphire 蓝宝石 Sillimanite 硅线石 Smithsonite 菱锌矿 Smoky Quartz 烟水晶 South sea Pearl 南洋珠 Spessortite 锰铝榴石 Sphene 榍石 Spinel 尖晶石 Spodumene 锂辉石 Talc 滑石 Tanzanite 丹泉石 Topaz 黄玉、拓帕石 Tourmaline 碧玺、电气石 Tremolite 透闪石 Zircon。
3.珍珠是怎么形成的英语作文
The birth of a pearl is truly a miraculous event. Unlike gemstones or precious metals that must be mined from the earth, pearls are grown by live oysters far below the surface of the sea. Gemstones must be cut and polished to bring out their beauty. But pearls need no such treatment to reveal their loveliness. They are born from oysters complete — with a shimmering iridescence, lustre and soft inner glow unlike any other gem on earth.A natural pearl begins its life as a foreign object, such as a parasite or piece of shell that accidentally lodges itself in an oyster’s soft inner body where it cannot be expelled. To ease this irritant, the oyster’s body takes defensive action. The oyster begins to secrete a smooth, hard crystalline substance around the irritant in order to protect itself. This substance is called “nacre.” As long as the irritant remains within its body, the oyster will continue to secrete nacre around it, layer upon layer. Over time, the irritant will be completely encased by the silky crystalline coatings. And the result, ultimately, is the lovely and lustrous gem called a pearl.How something so wondrous emerges from an oyster’s way of protecting itself is one of nature’s loveliest surprises. For the nacre is not just a soothing substance. It is composed of microscopic crystals of calcium carbonate, aligned perfectly with one another, so that light passing along the axis of one crystal is reflected and refracted by another to produce a rainbow of light and color.Cultured pearls share the same properties as natural pearls. Oysters form cultured pearls in an almost identical fashion. The only difference is a person carefully implants the irritant in the oyster, rather than leaving it to chance. We then step aside and let nature create its miracle.。
4.保护the pearl river的英语作文
In recent years, China’s food industry occurs security issus frequently, which makes people worried and lose confidence. Food safety, related to the people’s health, safety and healthy development of economy, is the major issue of national stability and social development. Since the Sanlu Incident occurred in 2008, the entire society increasingly concerned about food safety issue. It was in this context th。
5.哪里又关于珍珠的英文文献
A pearl is a hard, roundish object produced within the soft tissue (specifically the mantle) of a living shelled mollusk. Just like the shell of mollusks, a pearl is composed of calcium carbonate in minute crystalline form, which has been deposited in concentric layers. The ideal pearl is perfectly round and smooth, but many other shapes of pearls (baroque pearls) occur.The finest quality natural pearls have been highly valued as gemstones and objects of beauty for many centuries, and because of this, the word pearl became a metaphor for something very rare, very fine, very admirable and very valuable.Almost any shelled mollusk can, by natural processes, produce some kind of “pearl” when an irritating microscopic object becomes trapped within the mollusk’s mantle folds, but virtually none of these “pearls” are valued as gemstones. Although malacologists may refer to these objects as “pearls”, gemologists classify them merely as calcareous concretions.A black pearl and a shell of the black-lipped pearl oyster Saltwater pearl oyster farm, Seram, IndonesiaNacreous pearls, the most desirable pearls, are produced by two groups of molluscan bivalves or clams. One family lives in the sea: the pearl oysters. The other, very different group of bivalves live in freshwater, and these are the river mussels; for example, see the freshwater pearl mussel.Saltwater pearls can grow in several species of marine pearl oysters in the family Pteriidae. Freshwater pearls grow within certain (but by no means all) species of freshwater mussels in the order Unionida, the families Unionidae and Margaritiferidae. These various species of bivalves are able to make nacreous pearls because they have a thick iridescent inner shell layer called “mother of pearl”, which is composed of nacre. The mantle tissue of a living bivalve can create a pearl in the same manner that it creates the pearly inner layer of the shell.Fine gem-quality saltwater and freshwater pearls can and do sometimes occur completely naturally in the wild state, but this is rare. Many hundreds of pearl oysters or pearl mussels have to be gathered and opened, and thus killed, in order to find even one wild pearl, and for many centuries that was the only way pearls were obtained. This was the main reason why pearls fetched such extraordinary prices in the past. In modern times however, almost all the pearls for sale were formed with a good deal of expert intervention from human pearl farmers.A pearl being extracted from an akoya pearl oysterA nacreous pearl is made from layers of nacre, by the same living process as is used in the secretion of the mother of pearl which lines the shell. A “natural pearl” is one that formed without any human intervention at all, in the wild, and is very rare. A “cultured pearl”, on the other hand, is one that has been formed on a pearl farm. The great majority of pearls on the market are cultured pearls.Imitation or fake pearls are also widely sold in inexpensive jewelry, but the quality of the iridescence is usually very poor, and generally speaking, fake pearls are usually quite easy to distinguish from the real thing.Pearls have been harvested, or more recently cultivated, primarily for use in jewelry, but in the past they were also stitched onto lavish clothing, as worn, for example, by royalty. Pearls have also been crushed and used in cosmetics, medicines, or in paint formulations.Pearl is considered to be the birthstone for the month of June.。
6.急求全部关于珠宝的英文知识
红宝石（Ruby）
蓝宝石（Blue Sapphire）
祖母绿（Emerald）
彩色蓝宝石（Fancy Colored Sapphire）
碧玺（Tourmaline）
尖晶石（Spinel）
金绿宝石猫眼（Cat’s eye）
变石（Alexandrite）
海蓝宝（Aquamarine）
珊瑚（Coral）
黄晶（Citrine）
紫水晶（Amethyst）
石榴石（Garnet）
橄榄石（Peridot）
斑彩石（ammolite）
彩色钻石（Colored Diamond） 红碧玺（Rubellite）
绿碧玺（Verdelite）
蓝碧玺（Indicolite）
双色碧玺（Bi-Colored Tourmaline）
帕拉依巴碧玺（Paraiba）
坦桑石（Tanzanite）
托帕石（Topaz）
摩根石（Morganite）
锆石（Zircon）
堇青石（Dichroite）
绿柱石（Beryl）
金绿宝石（Chrysoberyl）
绿松石（Turquoise）
欧泊（Opal）
7.怎么用最简单的几句英语介绍珍珠
A pearl is a hard object produced within the soft tissue of a living shelled clam. The ideal pearl is perfectly round and smooth, but many other shapes occur. The finest quality natural pearls have been highly valued as gemstones and objects of beauty for many centuries. Because of this, pearl has become a metaphor for something rare, fine, admirable and valuable。
8.保护海洋的英语文章
Oceans becoming more acidicThe world’s oceans are slowly getting more acidic, say scientists.The researchers from California say the change is taking place in response to higher levels of carbon dioxide in the atmosphere.The lowering of the waters’ pH value is not great at the moment but could pose a serious threat to current marine life if it continues, they warn.Ken Caldeira and Michael Wickett, from the Lawrence Livermore National Laboratory, report their concerns in the journal Nature.Increasing use of fossil fuels means more carbon dioxide is going into the air, and most of it will eventually be absorbed by seawater. Once in the water, it reacts to form carbonic acid.Scientists believe that the oceans have already become slightly more acidic over the last century.But these researchers have tried to predict what will happen in the future by combining what we know about the history of the oceans with computer models of climate change.”This level of acidity will get much more extreme in the future if we continue releasing CO2 into the atmosphere,” said Dr Caldeira.”And we predicted amounts of future acidity that exceed anything we saw over the last several hundred million years, apart from perhaps after rare catastrophic events such as asteroid impacts.”If carbon dioxide release continues unabated, ocean pH could be reduced by as much as 0.77 units, the authors warn.It is not absolutely clear what that means for marine life, however.Most organisms live near the surface, where the greatest pH change would be expected to occur, but deep-ocean lifeforms may be more sensitive to pH changes.Coral reefs and other organisms whose skeletons or shells contain calcium carbonate may be particularly affected, the team speculate. They could find it much more difficult to build these structures in water with a lower pH.In recent years some people have suggested deliberately storing carbon dioxide from power stations in the deep ocean as a way of curbing global warming.But Dr Caldeira said that such a strategy should now be re-considered.”Previously, most experts had looked at ocean absorption of carbon dioxide as a good thing – because in releasing CO2 into the atmosphere we warm the planet; and when CO2 is absorbed by the ocean, it reduces the amount of greenhouse warming. 科学家们说世界上的海洋正在慢慢变“酸”。
来自加利福尼亚的研究人员称这种变化是 由于大气中二氧化碳含量过高造成的。他们警告说，目前海水pH值下降还不是非常严重，但是如果继续下降的话会对现存的海洋生物造成严重的威胁。
来自美国罗兰士利弗摩亚国家实验室的肯·卡尔代罗和迈克尔·维克特在《自然》杂志上提出了他们对此事的关注。越来越多的石油消耗意味着更多的二氧化碳被排放到空气中，而且大部分最终将被海水吸收。
二氧化碳一旦进入水中，就会发生反应形成碳酸。科学家们认为海洋的酸性已经比上个世纪稍微大了一点。
这些研究者们结合所知的海洋历史以及气候变化的电脑模型，试图预测将来的变化。“如果我们继续向大气中排放二氧化碳的话，将来的酸性浓度会远远超标。”
卡尔代罗博士说。“而且我们估计将来酸的总量会比过去几亿年中人类所见到的任何东西都大，更不用说可能发生类似小行星撞击地球等罕见的大灾难之后了。”
研究者们警告说，如果不减少二氧化碳的排放量，海洋的pH值可能会降低0.77个单位。尽管这对海洋生命来说意味着什么还不是很清楚。
大多数生物生活在海洋表面，而海洋表面正是pH值预期变化最大的地方，但是深海生物可能对pH值的变化更加敏感。研究组推测，珊瑚礁和其它骨架或外壳中含有碳酸钙的生物受到的影响可能会格外明显，在pH值较低的水域中它们很难形成这些结构。
最近的几年中，有人蓄意建议将发电站释放的二氧化碳储藏到深海中，以此来抑制全球变暖。但是卡尔代罗博士说现在应该重新考虑这种策略。
“以前，大多数专家都将海洋吸收二氧化碳看作一件好事——因为将二氧化碳释放到大气中会使大气变暖，然而当二氧化碳被海洋吸收后，温室效应就会降低。”。
