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Taylor Harbin
01-26-2014, 03:05 AM
I have a situation envisioned where a character wants to assay a piece of gold he's found in a creek, but without sending it to a professional. He wants to keep the discovery quiet.

I've seen pictures of a kit that would presumably make it easier to narrow down the quality of the sample.

Here: http://en.wikipedia.org/wiki/Touchstone_(assaying_tool)

I cannot find any information if such kits existed in the 1890s, or who manufactured them. I know that the touchstone itself was made of something called basalt, and the test required the use of nitric and hydrochloric acid.

Does anyone know how long it would have taken to procure these items in the 1890s, from whom, and how the proceeder would have been done?

King Neptune
01-26-2014, 03:38 AM
They were readily available, but for things like that it might mean they could be ordered from two companies in North America. Where is the character trying to get one? A miner or prospector might have gotten one before going out to dig.

That kind of kit has been used since ancient times. A sample is rubbed against the stone, and the purity can be determined by the color of the mark.

Basalt is an igneous rock

http://en.wikipedia.org/wiki/Touchstone_%28assaying_tool%29

Taylor Harbin
01-26-2014, 03:50 AM
They were readily available, but for things like that it might mean they could be ordered from two companies in North America. Where is the character trying to get one? A miner or prospector might have gotten one before going out to dig.

That kind of kit has been used since ancient times. A sample is rubbed against the stone, and the purity can be determined by the color of the mark.

Basalt is an igneous rock

http://en.wikipedia.org/wiki/Touchstone_%28assaying_tool%29

The character is located in a fictional town near the Adirondack Mountains in New York state. Historically, no significant deposit of gold has ever been discovered there. He wants a kit because the state's law in 1776 (which still stands today) preemptively claimed all precious metals that might be found there.

Like I said, he's trying to do this covertly. I have not been able to determine if any places in New York sold them.

King Neptune
01-26-2014, 05:08 AM
The character is located in a fictional town near the Adirondack Mountains in New York state. Historically, no significant deposit of gold has ever been discovered there. He wants a kit because the state's law in 1776 (which still stands today) preemptively claimed all precious metals that might be found there.

Like I said, he's trying to do this covertly. I have not been able to determine if any places in New York sold them.

He should have been able to get a stone from Boston within a couple of days.

blacbird
01-26-2014, 01:01 PM
The purity of gold, or of gold-bearing rock samples, is measured by assay offices by determing the specific gravity (e.g., density) of the samples in question. Pure gold has a specific gravity of about 18, which is to say, 18X that of water, the standard, fixed at 1. Gold is much heavier than nearly all other metals*, and far heavier than the silicate minerals like quartz, with which it often occurs. So you determine the volume of the sample and its weight, and from that calculate the specific gravity. Native gold is never pure, but generally contains a small percentage of alloyed metals, copper, silver, etc.

I actually do this measurement in my university physical geology class labs, using a classic old two-platform balance and a set of brass weights. I don't do it for gold, because I ain't got none, but I do hve samples of heavy lead sulfide ore (sp.g. ~12) and lighter minerals (quartz is ~2.7). It really is pretty simple, and that's what assay offices did during the old days of gold rush. From the specific gravity of the sample, you can easily determine the quantity of gold it contains, and prospectors/miners got paid based on those calculations.

caw

*Platinum has a specific gravity of around 21, even heavier than gold. But it's also more valuable, so your sample being heavier than gold isn't a problem.

Taylor Harbin
01-27-2014, 02:09 AM
He should have been able to get a stone from Boston within a couple of days.

Could you be a little more specific? Would he send for it via the local store? Would he have a P.O. Box?

King Neptune
01-27-2014, 03:43 AM
Could you be a little more specific? Would he send for it via the local store? Would he have a P.O. Box?

He's your character, so you can give him a P. O. Box if you wish. He could also get delivery in general delivery or through a hardware store. Maybe the best way would be that he would ask about a touchstone at a hardware store, and he would be told that they didn't stock them, but he could order one through them and get it in two days.

Bolero
01-27-2014, 06:37 PM
Query - if he wants to keep the discovery quiet, wouldn't having a gold test kit sent to him be a giveaway to anyone unscrupulous at the kit company?
Also, if they have a return address on the package, or some sort of fancy company logo, that would be a giveaway at the post office.

Taylor Harbin
01-27-2014, 07:18 PM
Query - if he wants to keep the discovery quiet, wouldn't having a gold test kit sent to him be a giveaway to anyone unscrupulous at the kit company?
Also, if they have a return address on the package, or some sort of fancy company logo, that would be a giveaway at the post office.

Yeah, I had thought about that. I guess he could always get the local school teacher to do it under the ruse that he was going to use it for a lesson.

King Neptune
01-27-2014, 11:03 PM
Yeah, I had thought about that. I guess he could always get the local school teacher to do it under the ruse that he was going to use it for a lesson.

Jewelers and metal workers also use(d) touchstones. At that time a blacksmith would occasionally have used one. Chemists and pharmacists might have also had uses for one.

wandering
01-28-2014, 01:09 AM
Read down to gold discovery: http://en.wikipedia.org/wiki/James_W._Marshall