Shelf life of RI fluid?

Jewelry Discussion
1

I spoke to a goldsmith friend of mine who said that RI fluid has a
shelf life of maybe 2 years…does that sound right? I’m having
trouble getting readings with mine lately. Some stones, larger ones,
like quartz, but others, which should give a reading don’t, or give
it irregularly.

Jeanne
www.jeannius.com
www.rhodes-moen.com

2 
I spoke to a goldsmith friend of mine who said that RI fluid has a
shelf life of maybe 2 years....does that sound right? I'm having
trouble getting readings with mine lately. Some stones, larger
ones, like quartz, but others, which should give a reading don't,
or give it irregularly.

Your friend gave you some good info. I’ve never seen a shelf live
published for RI fluid, but have experienced the same thing you’re
experiencing.

Dave

3

The RI liquid tends to have a long shelf life as long as it is not
left in sunlight or extreme heat/cold. Severe temperature changes can
alter the chemical. It may change color but it still can be used.

Andy " The Tool Guy" Kroungold
Tool Sales / Technical
Stuller Inc
Phone 800-877-7777 ext. 94194
Fax 337-262-7791

4

read though this:

https://secure.2spi.com/catalog/ltmic/cargille-standard.shtml

jesse

5

I know that it turns colour over time, and starts off colourless to
light yellow. That and there is something they add in the bottle to
stop it oxiding as fast as pure methylene iodide will. So I suppose
that you would know then if your RI fluid is bad then when it turns
an orangy brown, then it has oxidized beyond being useful as in has
broken down into its decomposition products: Carbon Monoxide,
Hydrogen Iodide, and Carbon Dioxide. This could be the reason your
not getting good readings anymore. As for how long this takes I’m
not sure, I suppose this would depend on where you store it, I know
it’s suppose to be stored in a cool dark place and if the exposure to
air is minimalized it should in theory last quite awhile. But I’m
certainly no expert on this, but the colour check will at least let
you know the state of you fluid.

Hope this helps,

Zoe Hardisty

6

I agree with most others that it is difficult to determine the shelf
life of RI fluid but believe we can assume it will go bad in time.
This depends on lots of things…temperature, amount of light
subjected to, how often the lid is removed, how quickly it is
replaced. etc.

One thing I know for sure…it can weaken of change its
characteristics and it can also crystalize. Had a bottle not too long
ago that was only a few months old but it had crystalized and became
useless. Talked with the Cargille people and they advised it was
kaput!

At least, keep it in a cool dark place and when used, immediately
replace the lid firmly. That should prolong its usefulness.

Cheers from Don at The Charles Belle Studio in SOFL where simple
elegance IS fine jewelry! @coralnut2

7

I think mine was going bad already, but then I had it in a “too
cool” location which is what crystalized it…It will read fine for
quartz, but doesn’t seem to read consistantly or strongly on higher
RI stones like corrundum etc. I ordered a new bottle.

thanks,
Jeanne
www.jeannius.com
www.rhodes-moen.com