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<p>[QUOTE="GoldFinger1969, post: 8346536, member: 73489"]<b><u>From the Saint-Gaudens Double Eagle book (and this might ONLY apply to Saints, not saying it applies to other coins from that era or coins struck decades later):</u></b></p><p><b><u><br /></u></b></p><p><i>"Luster......is the visual result of light reflecting off of thousands of tiny ridges and grooves of metal in the smooth (field) areas of a coin. These imperfections were created in a working die as the hard steel was stressed during the striking of thousands of blank planchets.</i></p><p><br /></p><p><i>The original surface of a coinage die is smooth....and largely free of imperfections.....The pressure, or force, applied to the planchet was approximately 100-120 tons per square inch.....<b>with each blow of the die, an imperceptible movement occured in the crystals of the die face. </b></i></p><p><br /></p><p><i><b>Following several hundred strikes, the die face had distored slightly so that the fields were no longer completely smooth, but consisted of miscroscopic ridges and grooves.</b></i></p><p><br /></p><p><i>This type of surface alteration was most prominent in the fields of a die where movement of the metal was greatest and least inhibited by details of the design. The portrait, inscriptions, and other design elements were sujbect to similar die deformation, but at a much lower rate and magnitude. This explains why a coin shows luster in the fields but not in the raised areas."</i>[/QUOTE]</p><p><br /></p>
[QUOTE="GoldFinger1969, post: 8346536, member: 73489"][B][U]From the Saint-Gaudens Double Eagle book (and this might ONLY apply to Saints, not saying it applies to other coins from that era or coins struck decades later): [/U][/B] [I]"Luster......is the visual result of light reflecting off of thousands of tiny ridges and grooves of metal in the smooth (field) areas of a coin. These imperfections were created in a working die as the hard steel was stressed during the striking of thousands of blank planchets.[/I] [I]The original surface of a coinage die is smooth....and largely free of imperfections.....The pressure, or force, applied to the planchet was approximately 100-120 tons per square inch.....[B]with each blow of the die, an imperceptible movement occured in the crystals of the die face. [/B][/I] [I][B]Following several hundred strikes, the die face had distored slightly so that the fields were no longer completely smooth, but consisted of miscroscopic ridges and grooves.[/B][/I] [I]This type of surface alteration was most prominent in the fields of a die where movement of the metal was greatest and least inhibited by details of the design. The portrait, inscriptions, and other design elements were sujbect to similar die deformation, but at a much lower rate and magnitude. This explains why a coin shows luster in the fields but not in the raised areas."[/I][/QUOTE]
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