New Trick, Old Dog

[Bubbles]

As a new member to this forum, I think this group rocks!

Here's another way of figuring karat values which I haven't seen mentioned in previous postings. I wonder if other members of this group utilize specific gravity to determine their gold karat values?

One of my favorite ways of figuring karat value is by measuring an item's specific gravity. It's not as complicated as it sounds. The classic formula for measuring specific gravity of an item is fairly straight forward. Air weight divided by the product of the subtraction of the item's water weight from it's air weight equals an item's specific gravity. To wit, as follows:

Step # 1: Weigh the item. This is referred to as it's "air weight".

Step # 2: Weigh the item while submersed in water. This is referred to as it's "water weight".

Step #3: Subtract the "water weight" from it's "air weight". This referred to as it's "s. g. factor number".

Step # 4: Divide the "air weight" by the "s. g. factor value"

The resulting number is the specific gravity of the item in question.

Of course, one may, alternatively, utilize electronic devices or acids to measure the karat value of gold items Electronic devices, however, are not infallible. A touchstone and acid can give good results but can be potentially hazardous. Moreover, acids that have been sitting around awhile can lose some of it's pizazz over time, slightly skewering results.

Measuring the specific gravity of a gold item as a way of determining it's karat value is not all that complicated or difficult. And it provides very accurate karat value test results.

 

[woodwizard]

thanks first I heard of this method but like it as it's safer and cleaner

 

[GENE EDWARDS]

Well I was doing just fine till I put the ring on my small scales and put it underwater. Then all Heck broke loose! Gene

 

[Bubbles]

Not only "safer and cleaner" Woodwizard, but the resulting s.g. measurement is more precise and accurate than any other method. It can be particularly useful when trying to figure the karat authenticity of gold plated items, without resorting to filing unsightly notches. The bugaboo with this method is coming-up with an easy, reliable and inexpensive way of weighing an item submersed in water.

 

[Bubbles]

Just a guess, Gene, but that wasn't an electronic scale you submersed underwater, was it? If so, this may come as a shock for you to realize, but water and electricity simply don't mix too good. As a rejection of the notion that every worthwhile new invention needs a battery or an extension cord, I've developed a couple of manual (non-electric!) specific gravity underwater measuring scales. But you may also track down a book written by the renowned American mineralogist, John Sinkankas, entitled MINERALOGY FOR AMATEURS for plans to build your very own inexpensive specific gravity measuring device, if you like.

You may not be old enough to recall that back in the good-ole-days, when women wore panty hose and men didn't, the corner grocer would weight a pound a tomatoes on a non-electric hanging scale. That's the kind of scale you want to use under water.

I've actually got one of those hanging vegetable scales which I use for measuring the specific gravity of rock boulders. Great for separating nephrite from jadeite. Hang the boulder from the hook at the bottom of the tomato scale, that's the "air weight". While the boulder is in suspension, hanging on the hook down below the scale, I come-up from down below with a bucket of water. Gently and carefully raising the bucket of water until the boulder is just barely totally submersed underneath the surface of the water, gives the "water weight" of the boulder in question.

The tomato scale is also excellent for weighing, besides boulders, those larger gold bars and ingots people have stashed under their lumpy mattresses.

 

[grumpyolman]

Thanks for sharing. Sounds like a lot better way to get set up rather than using acid or relying on a 3rd party to tell you value of your find. jim

 

[seeker41]

 

[Goldak]

This is pretty cool Bubbles. I'll have to get an accurate hanging scale and try this on some of my unstamped rings. Thanks!

 

[GENE EDWARDS]

Bubbles, I was just being funny, I'm 60 so I remember the good ole day. It would be interesting to have a video posted of the process so we can watch it being done and explained in detail. My battery scales are just fine, and so is my diamond tester, LOL. Sorry I made you think I was a dummy, Gene