Silvery tint appearance on the cornet

C

crauther

New Member
#1
It has been noted after the annealing a silvery tint shade on all cornets in that section. The density of acid is 1.2 and 1.3 with parting time 15 minutes each.
 
fireguy

fireguy

Supermoderator
#2
Is this "silvery tint" on the dore bead before parting? Or on the material after parting? Do you have a picture that might show this?
 
C

crauther

New Member
#3
Those silvery tint appearance not on the dore bead but on the cornet, after parting. I will do my best to post the picture, but right now am obliged to surrender my phone before log in, to the lab.
 
fireguy

fireguy

Supermoderator
#4
It has been noted after the annealing a silvery tint shade on all cornets in that section. The density of acid is 1.2 and 1.3 with parting time 15 minutes each.
It could be retained lead due to incomplete cupellation? If you wrap in lead foil, and re-cupel, does the silvery tint go away? If not lead, then perhaps other precious metal? You could do an ICP analysis for the other Pt group metals.
 
C

crauther

New Member
#5
It could be retained lead due to incomplete cupellation? If you wrap in lead foil, and re-cupel, does the silvery tint go away? If not lead, then perhaps other precious metal? You could do an ICP analysis for the other Pt group metals.
We had produced those cornets to the XRF analysis instead of ICP, and the result is 999.9 gold. There is no sign of pt group metals also. Will incomplete cupellation leads to silvery tint appearance on the cornet?
 
fireguy

fireguy

Supermoderator
#6
We had produced those cornets to the XRF analysis instead of ICP, and the result is 999.9 gold. There is no sign of pt group metals also. Will incomplete cupellation leads to silvery tint appearance on the cornet?
Incomplete cupellation will cause lead retention in the dore button. This could appear as a silvery tint depending on the amount of retained lead. If you notice this, and weigh the bead, and then recupel, you can see if the tint goes away and if the weight decreases.
 
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