據美國《探索》雜誌報導，當你在沙灘上漫步時，你總是會覺得有沙子夾在你的腳趾中間。大致一看，沙子似乎是一些微小的棕色岩石，也許摻雜有零星的貝殼和石頭。
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但沙子的真實模樣絕不是你所看到的這般普通，而是另有一段更為迷人的故事可說。在火山灰、侵蝕的山脈、死亡的生物體甚至老化的人造物體的組成中，沙子都能揭示當地環境的歷史，包括生物學和地質學方面的。以下是《探索》雜誌推出的11張精美絕倫的沙子圖片，可以讓我們一睹此微小世界裡的美麗景致。tvb now,tvbnow,bttvb4 h! R( I. n- y+ ?
科學家兼藝術家的蓋裡·格林伯格表示沙子能顯示與眾不同的顏色、形狀和質地。他用一台3D望遠鏡拍下這些沙子的美麗景致，編入了他今年初出版的新書《一粒沙子》中。
。Geriba Beach, Brazil
Worms have burrowed trails into this shell fragment. Worms like these are abundant in the ocean as well as on land. (Magnification 110x)
蠕蟲已經探查到潛入此貝殼碎片中的路徑。像這樣的蠕蟲在海洋和陸地上普遍存在。
Lumahai Beach, Kauai, Hawaii
Bright green olivine is a significant mineral in Hawaii's slow-flowing basaltic lava and is rich in iron. Its density allows it to separate from other sand grains in the rolling and depositing action of waves, which results in the accumulation that tints this beach a yellowish green. Dense sands like olivine are also resistant to weathering, allowing it to endure millennia of constant waves. (Magnification 110x)
淺綠色的橄欖石是夏威夷流動緩慢的玄武岩熔岩中的重要礦石，富含鐵。其密度大，可以讓它在滾動和沉降運動中和其它的沙粒分開，導致它以這種淺淺的黃綠色聚集在沙灘上。像橄欖石這樣的濃密沙粒還能抗風化，能經受得起百萬年的波浪衝刷。
Makena Point, Maui, Hawaii公仔箱論壇6 S1 v: B' `9 \# }8 u
This sand, red from iron oxide, was found at Makena Point, Maui. It eroded from igneous rock, which was produced by the solidification of molten magma. (Magnification 125x)
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這種沙粒的紅色來自氧化鐵。它是在毛伊島馬克蘭點（Makena Point）上發現的，是由火成岩侵蝕而成的。而火成岩是由熔化的岩漿凝固後形成的。
Maui, Hawaii
Not all sand is made of tiny bits of rock. Biogenic sand, which forms from the remains of marine life, is the major ingredient of many tropical beaches. The grains here are tiny fragments of a baby sea urchin shell.
The raised bumps on the white grain represent the sites of insertion for the sea urchin's spines. The blue grain has eroded to the point that the raised bumps have been completely rubbed off. (Magnification 100x)
並非所有的沙粒都是由微小岩石構成的，有些就是由海洋生物的屍體形成的，這也是許多熱帶海灘的主要成分。這些沙粒都是小海膽殼的微小碎片。其中，白色沙粒上面的圓形突起表明此位置是海膽脊骨的附著處。而藍色沙粒已經被侵蝕了，上面的突起基本上抹平了。TVBNOW 含有熱門話題，最新最快電視，軟體，遊戲，電影，動漫及日常生活及興趣交流等資訊。! e2 i) F9 W' `3 w b1 F
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The glasslike needles are sponge spicules, which form the internal skeletons of sponges. They are made of silica, can be found in a variety of bizarre shapes (including spiders and fishhooks), and are hard and sharp enough to cut through human flesh.* I$ ~4 r! w$ o" f1 ?
They surround the tip of a spiral shell, composed primarily of calcium carbonate, that has broken off and eroded. (Magnification 70x)這種玻璃似的針是海綿的小針突，由硅石組成，是用來支持軟組織的。它們有許多奇異的形狀，包括蜘蛛形和魚鉤形。這些小針突很堅硬也很鋒利，足夠可以切開我們人類的肉體。它們長在螺旋形甲殼頂端的四周。甲殼主要是由碳酸鈣組成，容易折斷和侵蝕。
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Some sand comes from decidedly less artistic human activity. Here, a small grain of copper is impacted into a larger nugget, also of copper. These grains precipitated downwind of an unregulated, smoke-belching copper smelter. (Magnification 110x)
一些沙粒直接來自非藝術家的活動中。這裡有一顆小銅粒被一塊較大的銅塊包裹著。這些銅粒是從沒有控制的冒煙銅熔爐中順風滴落下來的。
Northern Sahara, Morocco5.39.217.77:8898& ?" i+ J+ T! p, p- [% Y6 M
The pitted and frosted surface of these grains is typical of desert sand, where grains constantly collide with one another. Many desert sands have a faint red color caused by a thin layer of iron that precipitates from the atmosphere and coats the grains. (Magnification 85x)
這些表面有凹痕和冰霜的沙粒上是典型的沙漠沙粒。沙漠中的沙子持續地相互碰撞。許多沙漠的沙子有淡淡的紅色，這是由一層薄薄的鐵導致的。而這些鐵是從大氣中沉澱下來的，覆蓋在這些沙子上面。0 P& L" I( W6 |9 Z- i3 o
Plum Island, Massachusetts4 G# r0 Y B: m; |) j
Metamorphic minerals, which form at high temperatures and pressures underground, can become heavy, brightly colored sands like these. But color is often unreliable for identifying different types of sands. 1 F/ C4 H# w2 P' \$ J' r7 p
Here, the pink and red grains are garnet, but garnet can also be brown, black, green, or orange, depending on the chemistry. The bright green epidote in the center can also be gray, brown, or nearly black. The angular, black magnetite--the most common naturally occurring magnetic material on earth--is always black, however, and is frequently found near garnet. (Magnification 95x)
在地下高溫高壓環境下形成的這些可變形的礦石能成為明亮的深色沙粒，但它們的顏色通常是不穩定的，由此可以識別不同種類的沙粒。在這裡，粉紅色和紅色的沙粒是石榴石，但石榴石也能根據其化學物質的不同而呈現出褐色、黑色、綠色或黃色。
中間淺綠色的綠簾石也能變成灰色、棕色或近黑色的。角形的黑色磁鐵礦是地球上最常見的天然磁性材料。它們總是黑色的，常常出現在石榴石的附近。/ Z! l) X6 a4 W3 h3 F- B4 y
Taketomi Island, Okinawa, Japan公仔箱論壇: z; j3 ~ w5 k* R N# O
Looking like a puffy white star studded with little pearls, this is the shell of an amoeboid protist called a foraminifera, or foram. An estimated four thousand types of forams live in the world's oceans.
The shells, called tests, are made mainly of calcium carbonate, which the animals derive from carbon atoms in the air and water. Forams thus play a significant role in the carbon cycle. (Magnification 75x)
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這看起來像一顆膨脹的白色星星，上面布滿小小的珍珠，但其實是原生動物有孔蟲的外殼。這種有孔蟲估計可能在海洋中生活了4千年。其甲殼主要是由碳酸鈣組成，而碳酸鈣中的碳是由它們從空氣和水中獲取的。因此，有孔蟲在碳循環中起了重要的作用。5.39.217.77:8898* `6 ]: C. G% j5 w2 B2 g1 d
Delos Island, Greece
Man-made objects can also become sand. This grain was found on the Greek island of Delos, one of the most important mythological, historical, and archaeological sites in Greece. tvb now,tvbnow,bttvb2 P3 ]) j5 P& D
Delos had no indigenous marble, and an enormous amount of marble had to be quarried and brought to the island to erect the temples. Over the years, the marble blocks have eroded and the local beaches are now peppered with different types of marble. (Magnification 130x)
人造物體也能成為沙粒。此沙粒是在希臘的得洛斯島上發現的，這裡是希臘最重要的神話、歷史和考古場所。得洛斯島沒有本地大理石，但大量的大理石被採集並運送到此島上修建廟宇。多年來，這些大理石被侵蝕，而今當地的海灘到處是不同種類的大理石。 n) G |2 G' A& z0 X: N! v
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