Diamonds getting Milky

Jewelry Discussion
1

Hi everybody

I am Ganesh from Titan Industries Ltd, India. I am Interested in
knowing about the changes happening to Diamond physically during
Stone-in-place casting and the parameters which affect the
Quality of the Diamond - Milky appearance of Diamonds after casting.
Thank you in advance for your valuable inputs.

Regards

P.Ganesh
Titan Industries Ltd,India.
+914344554736

2

Ganesh,

The problem with your diamonds is that you are ‘smoking’ them. If
you look at them closely, you will see that it is not a problem with
reducing the grade but is a surface coating which is not removable.
This happens when enough heat is applied to a diamond that it turns
red. Diamonds can take quite a lot of heat as long as they are heated
as well as cooled slowly. Uneven heating to this red stage will also
cause internal shattering.

I have never tried casting in place but my guess is that: A) Your
gold is too hot. Seems to me that to avoid rapid heating, you must
have a very close tolerance between the temp of the mold and the
temp of the gold. And B) You are trying to use large diamonds. I find
that above say; 3 -3.5mm diamonds, they do not conduct heat evenly
enough to avoid this.

3

Hello Ganesh,

I am Interested in knowing about the changes happening to Diamond
physically during Stone-in-place casting and the parameters which
affect the Quality of the Diamond - Milky appearance of Diamonds
after casting.

Sounds like the diamonds got burned…each stone would have to be
repolished

RD

4

Your burn out is to high. Use longer lower burn outs stay to about
900 F, Your melt must be just barley melt most try to use to hot
melt.

Don in Idaho
Just back from seeing my doughter in Verginia.