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Gold Prospecting
Metal Detecting for Gold
Specific gravity test for specimens and minerals
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<blockquote data-quote="user 4386" data-source="post: 650835" data-attributes="member: 4386"><p>Yes, that is the method I outlined nearly five years ago (Apr 13 2018) in :</p><p></p><p><a href="https://www.prospectingaustralia.com/threads/series-on-identifying-minerals.24758/page-2#post-404574" target="_blank"><strong>Series on identifying minerals - part 8 SPECIFIC GRAVITY</strong></a></p><p></p><p>Except that on my digital scale I simply zero out the container full of water before weighing the specimen in it. So I directly get a figure for the specimen in air, then one in water.</p><p></p><p>Otherwise it is just Archimedes Principle "<strong>the buoyant force on a submerged object is equal to the weight of the fluid that is displaced by the object".</strong></p><p></p><p>i.e. pressure at depth in a fluid =rho (Greek symbol) x g x h where rho =1 for water (a constant, its density), g is the gravitational constant (so does not vary) and h the depth (a variable). The last is therefore the only thing varying, and the pressure at the bottom of the specimen is greater than the pressure at the top of the specimen, because pressure increases with increased depth. Pressure is force per unit area, so this difference is the bouyancy force (per unit area) which makes it appear to weigh less in water than in air because it will be greater at the bottom of the specimen than at the top (an upward force).</p><p></p><p>I think.....</p></blockquote><p></p>
[QUOTE="user 4386, post: 650835, member: 4386"] Yes, that is the method I outlined nearly five years ago (Apr 13 2018) in : [URL='https://www.prospectingaustralia.com/threads/series-on-identifying-minerals.24758/page-2#post-404574'][B]Series on identifying minerals - part 8 SPECIFIC GRAVITY[/B][/URL] Except that on my digital scale I simply zero out the container full of water before weighing the specimen in it. So I directly get a figure for the specimen in air, then one in water. Otherwise it is just Archimedes Principle "[B]the buoyant force on a submerged object is equal to the weight of the fluid that is displaced by the object".[/B] i.e. pressure at depth in a fluid =rho (Greek symbol) x g x h where rho =1 for water (a constant, its density), g is the gravitational constant (so does not vary) and h the depth (a variable). The last is therefore the only thing varying, and the pressure at the bottom of the specimen is greater than the pressure at the top of the specimen, because pressure increases with increased depth. Pressure is force per unit area, so this difference is the bouyancy force (per unit area) which makes it appear to weigh less in water than in air because it will be greater at the bottom of the specimen than at the top (an upward force). I think..... [/QUOTE]
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Gold Prospecting
Metal Detecting for Gold
Specific gravity test for specimens and minerals
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