Determining baroque pearl weight???

[DmDrew]

I am trying to find info on how to determine a Baroque pearls weight,I need to know to deduct that weight from a necklace that has a lot of gold within the spacing of the pearls,Also,if anyone could give me a ballpark on the value of golden baroque south sea pearls,Thank you

 

[pearlsngems]

Just asking the obvious here: do you have a jewelry scale or postal scale?
Also the value has a lot to do with the size and other qualities of the pearl.

 

[DmDrew]

I do have a jewelry scale,and a digital caliper,I realize there are many factors that determine a pearls value,I am just looking for a ballpark range( low to high quality),just trying to get a rough idea of the material value of the piece,Thanks for your reply btw

 

[LilAlex]

If they are baroque, can we assume that they are natural and not cultured? I see a density of 2.73 for natural pearls. I see a density of 14K gold that is 12.9 - 14.6, depending upon the alloy. (You can Google values for 18K, etc.)

Sounds like you mostly want to know the gold value ("deduct that weight" of the pearls). Channeling my inner Archimedes, I think you could put it in a as narrow a graduated cylinder as would fit and add 10 mL (= 10 g) of water -- or whatever minimal volume just ensures that the piece is completely submerged -- and, using the meniscus, see what the final volume of water + necklace is. You could then determine the volume of the brooch and the mass of the brooch and calculate its "average density." With that number, you can see how much of the mass (weight) is pearl and how much is alloyed gold. (If they are cultured peals, that may introduce another "degree of freedom" that makes the answer too suspect -- unless there are great data somewhere for the density of cultured pearls.)

Dense fluids are used to determine gem density (I think), but I doubt those would go anywhere near the density of your gold-heavy piece -- except for mercury and that's no fun.

Or: you could weigh it in air and then in water (or a fluid with known density) like the pros do. ("When a body is immersed in a fluid, partially or wholly, it experiences an upward force equal to the weight of the volume of the fluid displaced by it.") The difference in g is how many mL of water are displaced, which is the volume of the piece.

Or: someone who does this a bunch could probably eyeball it for you. If it's a pawn shop or gold salvage place, I would not trust their estimate unless they proposed to weigh it after.

If a lot of the volume is some third substance with an unknown density, none of these will work.

 

[Pearlescence]

If they are baroque, can we assume that they are natural and not cultured? I see a density of 2.73 for natural pearls. I see a density of 14K gold that is 12.9 - 14.6, depending upon the alloy. (You can Google values for 18K, etc.)

Sounds like you mostly want to know the gold value ("deduct that weight" of the pearls). Channeling my inner Archimedes, I think you could put it in a as narrow a graduated cylinder as would fit and add 10 mL (= 10 g) of water -- or whatever minimal volume just ensures that the piece is completely submerged -- and, using the meniscus, see what the final volume of water + necklace is. You could then determine the volume of the brooch and the mass of the brooch and calculate its "average density." With that number, you can see how much of the mass (weight) is pearl and how much is alloyed gold. (If they are cultured peals, that may introduce another "degree of freedom" that makes the answer too suspect -- unless there are great data somewhere for the density of cultured pearls.)

Dense fluids are used to determine gem density (I think), but I doubt those would go anywhere near the density of your gold-heavy piece -- except for mercury and that's no fun.

Or: you could weigh it in air and then in water (or a fluid with known density) like the pros do. ("When a body is immersed in a fluid, partially or wholly, it experiences an upward force equal to the weight of the volume of the fluid displaced by it.") The difference in g is how many mL of water are displaced, which is the volume of the piece.

Or: someone who does this a bunch could probably eyeball it for you. If it's a pawn shop or gold salvage place, I would not trust their estimate unless they proposed to weigh it after.

If a lot of the volume is some third substance with an unknown density, none of these will work.

Why assume they are natural. It is unlikely they are natural. most baroque SS (or any pearls for that matter) are cultured.
It would be easier and far more accurate for the OP simply to take the piece apart, perform whatever computations he wants on the components, then re-assemble

 

[dk168]

Easier to find out the size of the spacing beads using a pair of callipers, and look for the gold weight via sites that sell gold findings.

Not possible to guestimate the total weight of baroque pearls as each pearl will be different, being baroque in nature!

DK

 

[Pearlescence]

Plus there is no such thing as a ball-park value for any pearls. Retail, wholesale, new, second hand, for insurance...all different. Then there are the permutations of quality. Basically what you are asking is how long that piece of string is.

 

[lovedogs]

Yeah, we can't give a ballpark unfortunately. Just too many variables

 

[LilAlex]

It would be easier and far more accurate for the OP simply to take the piece apart, perform whatever computations he wants on the components, then re-assemble

Oh well sure that makes perfect sense and all and is way better than my answer but where's the challenge?! Huh?