Message:

<p>[QUOTE=&quot;Michael H Webb, post: 3236006, member: 93313&quot;]The Navajo Indians have refined the techniques of sand-cast molding silver jewelry. First, a sand-cast mold is created to add an exaggerated relief, at the cost of obscuring fine detail. Then, a &quot;master coin&quot; is cast (using silver, for example, with a melting point of 1763°F). Then, a second mold is created using a suitable metal or alloy with a melting point that is lower than that the master coin (lead, for example, has a melting point of 621.4°F).&nbsp; It is this secondary mold that is polished flat to lend a mirrored background to the solder-molded coin.</p><p><br /></p><p>Additionally, the coin is molded from an alloy that is harder than lead, but still soft enough to write with, as this image shows:</p><p><img src="https://i.imgur.com/4UPuKtf.jpg" class="bbCodeImage wysiwygImage" alt="" unselectable="on" /></p><p><br /></p><p>Finally, in addition to its softness, the metal must appear silver enough to fool you.</p><p><br /></p><p>60/40 tin/lead solder fulfills all of these requirements with a melting point of 370°F.</p><p><br /></p><p>A specific gravity test produced results congruent with this hypothesis within the tolerance prescribed by measuring the specific gravity of a genuine coin known to be pure silver.</p><p><br /></p><p>The volume of the sand-cast molded coin is ~5.78 cc while the genuine coin&#039;s volume is ~4.13 cc. This difference in volume is congruent with a mold that has been polished flat.</p><p><br /></p><p>Also, notice how rough the reeded edge actually is:</p><p><img src="https://i.imgur.com/FRdFuIh.jpg" class="bbCodeImage wysiwygImage" alt="" unselectable="on" /></p><p>The coin was first cast, then a machine cut grooves at precision intervals, resulting in silver like flakes which fell from the coin.</p><p><br /></p><p>A mold mark is additional evidence of the cast.[/QUOTE]</p><p><br /></p>

Your name or email address:

Do you already have an account?

• No, create an account now.
• Yes, my password is:
• Forgot your password?

Stay logged in