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Gold Prospecting
Metal Detecting for Gold
Specific Gravity test help - Gold and quartz
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<blockquote data-quote="Hawkear" data-source="post: 676461" data-attributes="member: 4728"><p>There are some formulae around that purport to calculate gold content but these are generally arithmetic formulae and estimatory and often translated into plug in applications. The true relative content can only be obtained by calculus methods. </p><p>Calculus is based on common sense idea of doing progressive estimations to approach a true value limit. </p><p>All you have to do is assume that the entire specimen volume (easily obtained by the water uplift method) is composed of quartz. If so what weight should that volume of quartz weigh? That is easily obtained by multiplying the volume by the SG of quartz. Obviously any weight more than that should be gold.</p><p>Then ask yourself, if not all the volume was quartz what volume does that estimated weight of gold occupy? That is also easy to calculate by dividing that weight by gold’s SG and that volume then has to be subtracted from the volume we just assumed to be fully occupied by quartz. </p><p> When this newer estimation of quartz volume is made a revised and more accurate estimation of gold weight can be made.</p><p>This process can be repeated as many times as wanted to give an ever increasing accurate gold content figure. After about 4 iterations however no significant change in the gold content will be noted as this is the calculus limit. </p><p>In practice only about 3 iterations are necessary as natural variations in gold and quartz SGs may be present as well as measurement errors.</p></blockquote><p></p>
[QUOTE="Hawkear, post: 676461, member: 4728"] There are some formulae around that purport to calculate gold content but these are generally arithmetic formulae and estimatory and often translated into plug in applications. The true relative content can only be obtained by calculus methods. Calculus is based on common sense idea of doing progressive estimations to approach a true value limit. All you have to do is assume that the entire specimen volume (easily obtained by the water uplift method) is composed of quartz. If so what weight should that volume of quartz weigh? That is easily obtained by multiplying the volume by the SG of quartz. Obviously any weight more than that should be gold. Then ask yourself, if not all the volume was quartz what volume does that estimated weight of gold occupy? That is also easy to calculate by dividing that weight by gold’s SG and that volume then has to be subtracted from the volume we just assumed to be fully occupied by quartz. When this newer estimation of quartz volume is made a revised and more accurate estimation of gold weight can be made. This process can be repeated as many times as wanted to give an ever increasing accurate gold content figure. After about 4 iterations however no significant change in the gold content will be noted as this is the calculus limit. In practice only about 3 iterations are necessary as natural variations in gold and quartz SGs may be present as well as measurement errors. [/QUOTE]
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Gold Prospecting
Metal Detecting for Gold
Specific Gravity test help - Gold and quartz
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