Amethyst

紫水晶

This large geode structure of amethyst is on display in the Smithsonian Museum of Natural History. Amethyst is a variety of quartz with the characteristic composition SiO₂, but distinctive and popular for its dramatic purple color.

这种大型的紫水晶钟乳结构陈列在史密森尼自然历史博物馆中。紫水晶是二氧化硅的一种变种，但因其鲜明的紫色而独具特色且广受欢迎。

This geode is about 40x35 cm and is from Rio Grande do Sul, Brazil. It is described as amethyst formed with calcite.

这个地质体大约是40厘米乘35厘米，来自巴西的圣路易斯-杜-桑托斯。它被描述为由石英形成的紫水晶。

This interesting formation of amethyst quartz crystals is about 24x40 cm and is from Sweden, Maine.

这种有趣的石英晶体排列尺寸约为24x40厘米，来自缅因州。

This is a closer view of one of the crystal clusters of the sample at left.

这是左侧样品中一个晶体簇的更清晰视图。

The large single crystal of amethyst at right is about 4x4 cm and is from North Carolina. The gem below it is 1362 carats and is from Jacobea mine, Bahia, Brazil. The sample extreme right is about 17x15 cm and is from Diamond Willow mine, Pearl, Ontario,Canada.

右侧的较大单晶体紫水晶约为4x4厘米，来自北卡罗来纳州。其下的是1362克拉的宝石，来自巴西巴希亚州的Jacobea矿。最右侧的样品约为17x15厘米，来自加拿大安大略省佩尔的Diamond Willow矿。

This sample is about 10x7 cm and is from Vera Cruz, Mexico.

这个样本大约是10×7厘米，来自墨西哥韦拉克鲁斯。

This huge display of amethyst crystals is about 60x60 cm and is from Guerrero, Mexico.

这块巨大的紫水晶晶体展示区约为60厘米见方，来自墨西哥格鲁埃罗州。

This sample of amethyst is about 7x7 cm. It is from Rio Grande do Sul, Brazil

这块紫水晶样本大约是7厘米见方。它来自巴西的圣路易斯-杜-桑托斯。

This example of amethyst crystals is about 35x40 cm. It is presumed that amethyst crystals formed first in an underground cavity from water containing dissolved silica. Later, another solution entered the cavity and formed the calcite crystals on top.

这些紫水晶晶体大约35厘米×40厘米。假设这些紫水晶晶体最初是在地下洞穴中由含有溶解二氧化硅的水形成。之后，另一种溶液进入洞穴，在其上方形成了方解石晶体。

This large specimen of amethyst crystals is probably 60 cm across. It is from Serra do Mar, Rio Grande do Sul, Brazil. It was once part of a 32,000 kg (70,000 lb) geode.

这种大块的紫水晶晶体直径可能有60厘米。它产自巴西圣保罗州里约热内卢的马尔山。它曾是重达32,000千克（70,000磅）的钟乳石的一部分。