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SCOTT NO
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1106 A281
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DATE OF ISSUE
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1971 Sep 24
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FACE VALUE
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1e
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COUNTRY
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Portugal
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DESCRIPTION
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The stamp shows wolframite crystal. It is found in the form of prismatic crystals. It is an ore of tungsten. It is important in lamp filaments & in steel alloy cutting tools. It was issued for spanish portuguese american economic geology congress.
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GEMSTONE
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Wolframite
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VARIATION
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Used, Meter Mark, First Day Cover, Envelope
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