Microscope graduated slides for assay prills

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goldshark

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Does anybody know of a company that sells either slides with accurate size graduations, or the scope with a built in graduation, to measure the size of a tiny prill? For those that don't know, Gold has a characteristic that makes it almost perfectly round, when reduced in a cupel. For super tiny beads, which would normally require a super accurate scale (= expensive). A cheaper solution can be to use either the above, or a micrometer. Thanks in advance.
 
Pretty well all instrument makers will supply reticules for their instruments, choices range from the makers standard grids to custom grids depending on application.
These reticules are usually supplied with an etched glass slide to compare against when using a variable magnification instrument.
Deano
 
I bought an inexpensive USB microscope (under $20.00) that included a reticle. I haven't actually used the reticle, so I can't speak to its accuracy, but it might be worth taking a look at.

Dave
 
So I found the proper term for a graduated slide, it is called a "staged" slide. I was wondering if there was a 30x power lens, with an accurate reticle already installed, for assay work. Also trying to find the corresponding size to weight conversion chart, per assay ton. I have heard that with the reticle, you still need a staged slide to calibrate it. So a 30x hand lens, with accurate reticle would be what I am asking, if anybody knows of a supplier with the best bang per buck.
 
goldshark said:
Does anybody know of a company that sells either slides with accurate size graduations, or the scope with a built in graduation, to measure the size of a tiny prill? For those that don't know, Gold has a characteristic that makes it almost perfectly round, when reduced in a cupel. For super tiny beads, which would normally require a super accurate scale (= expensive). A cheaper solution can be to use either the above, or a micrometer. Thanks in advance.
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Hi Goldshark,

Check out Amazon for "microscope ruler".
 
Ok, got the staged slide down. I am wondering if there is a small ,accurate loupe type scope available. Also if there is a cheat sheet available that would equate size of prill to either grams per kilogram, or ounces per ton, already available. I know I can figure the math each time I get a prill, but it would be a time saver to have a cheat sheet.
 
goldshark said:
Ok, got the staged slide down. I am wondering if there is a small ,accurate loupe type scope available. Also if there is a cheat sheet available that would equate size of prill to either grams per kilogram, or ounces per ton, already available. I know I can figure the math each time I get a prill, but it would be a time saver to have a cheat sheet.
Click to expand...
I have seen prints and I think one can make an angled funnel like structure by two rulers or similar with markings, which can be read out directly.
Just slide the prill so it touches both rulers and read out the size.
 
goldshark said:
Ok, got the staged slide down. I am wondering if there is a small ,accurate loupe type scope available. Also if there is a cheat sheet available that would equate size of prill to either grams per kilogram, or ounces per ton, already available. I know I can figure the math each time I get a prill, but it would be a time saver to have a cheat sheet.
Click to expand...
I think I saw it in a book regarding fire assays, or maybe it was posted here.
There are calculators though. Diameter vs volume.
 
I have already, a micrometer. This is accurate to .001 of a millimeter, so I will probably go that route. Still looking for a cheat sheet for the grams per tonne. Thanks all.
 
I found Omnicalculator.com . You can measure your prill size with a digital set of calipers. Enter the values depending on wether you measured in inches or millimeters. Enter length, width, and thickness for all values (round prill ) the same number, scroll down to final requests. You can ask for the result in just about any weight system needed. It will save a lot of time with all the math. I hope this site remains active for a long time. Not a cheat sheet, but very helpful. You can also select any metal you want to figure the weight of, based on any cubic , or round dimensions. Gotta love the internet.
 
goldshark said:
The ratio of a sphere to a cube ( max sphere that will fit inside cube), is 11:21. If you use the sphere's dimension, multiply by .5238 to find final weight.
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Weight will be dependent on composition/alloy, ie ratio between Gold, Silver and other PMs
 
Yggdrasil said:
Weight will be dependent on composition/alloy, ie ratio between Gold, Silver and other PMs
Click to expand...
This thread is about finding a way to weigh the pure prills left from an assay, after cupeling, inquarting, parting and remelting, without a super expensive balance beam scale, costing many thousands of dollars, based purely on the spherical size. It should have a very high ( at least .999 fine), before it is sized for the weight. I hope this helps.
 
goldshark said:
This thread is about finding a way to weigh the pure prills left from an assay, after cupeling, inquarting, parting and remelting, without a super expensive balance beam scale, costing many thousands of dollars, based purely on the spherical size. It should have a very high ( at least .999 fine), before it is sized for the weight. I hope this helps.
Click to expand...
Yes, but unless you have full control of the composition of the prill, the only thing you will know for certain is the volume of the said prill.
Gold has a SG of 19.3
Silver has a SG of 10.5
Pt 21
Pd 12
So unless you know the mix you will not know the SG of said alloy.
 
I hear what you are saying, and yes, you are correct in this matter. I should have stated that this works after conducting an ICP or AA for presence of the PGM's. I was assuming these had been done, and the ore does not contain any of these elements. The ore is a typical western US sulphide, containing amounts of Au/Ag, and some base metals.After base metals are cupeled out, the prill is inquarted ,parted of Ag, remelted, leaving .999 Au only, which leaves a 19.3 SG. Thanks for bringing this to my, and others attention.
 
goldshark said:
I hear what you are saying, and yes, you are correct in this matter. I should have stated that this works after conducting an ICP or AA for presence of the PGM's. I was assuming these had been done, and the ore does not contain any of these elements. The ore is a typical western US sulphide, containing amounts of Au/Ag, and some base metals.After base metals are cupeled out, the prill is inquarted ,parted of Ag, remelted, leaving .999 Au only, which leaves a 19.3 SG. Thanks for bringing this to my, and others attention.
Click to expand...
Aah, I had not picked up this tiny bit of information, then it is quite straight forward 😀
 
For those that use calculations, Omnicalculator.com has over 3000 calculators for a great many subjects. I suggest you try them out. They are quite a site, and much needed for this forum.
 
Just priced a digital scale, accurate to weigh beads from assaying, down to .0001 of a gram accuracy. .0001 gram from a 1 assay ton sample, would represent 1/10th of an ounce of Au per ton. Cost = $47,500 + shipping and insurance. Nice scale I'm sure of. Hence the size/weight thread.
 

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