Iceland SPAR is a form of calcite that splits light into two beams.

冰洲石是方解石的一种存在形式，它可以把光线分成两束。

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Pictured here: Two polar bears spar, or play fight, in Churchill, Manitoba.

图为两只北极熊在争吵或打闹，摄于马尼托巴丘吉尔。

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Two polar bears SPAR in the snow as a magenta sunset descends over Churchill, Manitoba, Canada.

品红色的暮光降临到加拿大曼尼·托巴省的丘吉尔小镇，两只北极熊正在雪中打闹。

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Look for the exchange starting at around 2:30, in which the two spar over the issue of battery life.

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Iceland spar is a form of calcite that splits light into two beams.

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It has now been shown that it is of Iceland spar - a form of calcite known for its property of diffracting light into two separate rays.

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