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Ultrasonic stone safety


#1

I was told GIA did not recommend ultrasonic because of possible
flaws in stones, expecially diamonds. Can you clarify?

GIA classes stones as: safe, usually safe, risky & never, as far
as suitability for the ultrasonic cleaner. All classifications
are based on stones with no inclusions. The presence of
inclusions drops a stone to the risky or never class, depending
on the size & type of inclusion.

It’s never really safe to make blanket statements, especially
about things in the natural world, but here’s a gross overview.

There are a number of stones that should NEVER be placed in an
ultrasonic cleaner; oiled, highly included & those showing
fractures. There’s a large list of stones that even if they are
(or appear) perfect should never be put in an ultrasonic, most
notably, emerald. Additionally, no assembled (doublets, triplets
etc) stone should be subjected to ultrasonic cleaning.

Diamonds, corundum, garnets & spinels are usually safe. Jade,
hematite, YAG & CZ are safe.

All the rest of the stones are classed as either risky or never.

Dave


#2

This is really interesting, Dave! Thanks for sharing it! I’ve
been following the ultrasonic cleaning thread with great
interest, and I think you’ve all convinced me to buy one, even if
the other Dave is still on the fence(?).

Since you indicate all other stones are in the risky or never
categories, that would include the quartz family. I could see
how cryptocrystalline members (agates, chalcedony, etc.) could be
problematic, but what about crystalline quartz like amethyst?
No real cleavage plane problem, not usually fractured (in cut
stones). Any insight?

Most of my work contains stones… from rhodochrosite, to druzy
stones to turquoise to fossils. Does this mean I would have to
unset these before cleaning? Or more likely, revert to the ol’
toothbrush and detergent technique? That would certainly reduce
the benefit of the ultrasonic. I only occasionally work with the
traditional fine jewelry and precious gemstones.

Let me know what you think?

Dave Sebaste
Sebaste Studio
Charlotte, NC


#3

Dave said,

Since you indicate all other stones are in the risky or never
categories, that would include the quartz family.<<

Actually the quartz family has stuff in just about all
categories. Most of the solid stuff, eg. amethyst, citrine &
smokey are in the ‘usually safe’ category.

The GIA ‘Gem Reference Guide’, ISBN # 0-87311-019-6, has a
description of the more popular The description covers
lots of stuff only a gemologist would be interested in, but a gem
fanatic would find it interesting as well. It’s one of the texts
used in the GIA GG course. I don’t know if it’s available
outside the course or not. Try Susan Van De Vyvere (she’s the
bookstore mgr) at svandevy@gia.org.

Obviously, most everything (relative to ultrasonic safety) in
the book is on the conservative side. Nobody wants to say stone
xxxx is ultrasonic safe & then have someone put the crown jewels
in an ultrasonic cleaner & end up with a bunch of fish tank
gravel. Wouldn’t the lawyers love that!

I’ve put stones listed as ‘risky’ & ‘never’ in and had
absolutely nothing happen except they came out clean. One good
rule of thumb, ‘Don’t put anything in the ultrasonic you’re not
prepared to replace’.

Another Dave


#4

Gee, Dave,
The next thing you know you’ll be wanting a steam cleaner! (LOL!)
Wendy Newman (who ultrasonics and steams everything that can
handle it)


#5

Most of my work contains stones… from rhodochrosite, to druzy
stones to turquoise to fossils. Does this mean I would have to
unset these before cleaning?

Dave
You can place soft stones such as emerald and opal in an
ultrasonic for a few brief seconds and it will not harm them. If
you keep the stone in contact with your rubber tipped tweezers it
will negate some of the effects of the ultrasonic waves aginst
the stone. Just a few seconds is all you will need to clean most
pieces anyway. Just do not leave these pieces in for extended
times. Just a quick dip N swish. RED