Strange inclusions in Georgian diamonds

[Sherkatz]

Hello,
I recently purchased a lovely little brooch with the understanding that the stones are diamonds. However... The stones have very distinct black lines!! Is this a problem with the foil backing or are they not diamonds. I will try to have it tested, but being in southern France in August, I may not find a jeweler open

 

[Karl_K]

looks like ink on the stone to me.

 

[Mo Ro]

Hello,
I recently purchased a lovely little brooch with the understanding that the stones are diamonds. However... The stones have very distinct black lines!! Is this a problem with the foil backing or are they not diamonds. I will try to have it tested, but being in southern France in August, I may not find a jeweler open

Rutilated quartz?

 

[Rubymal]

It also looks like ink, but very strange. Have you tried cleaning it?

 

[GliderPoss]

It looks like rutilated quartz to me....

 

[Daisys and Diamonds]

its a very pretty brooch

 

[JPie]

I suspect that this brooch is not actually antique Georgian, but a modern reproduction. The reason I think so is because something about the style doesn’t quite match Georgian brooches that I’ve seen, and the metal looks like it’s been made to appear older than it is.

Could you share photos of the back of the brooch? That might give a better idea as to whether my hunch is right. Thank you!

 

[stonehunter20]

curious, what tool are you using to see those lines?

 

[stracci2000]

Another vote for rutilated quartz

 

[monipod]

I'm also thinking rutilated quartz.

And of course I had to google some and found this ring: https://www.annasheffield.com/products/bea-arrow-ring-blackened-rutilated-quartz-black-diamonds

Very similar in look. Gorgeous brooch.

 

[Daisys and Diamonds]

I'm also thinking rutilated quartz.

And of course I had to google some and found this ring: https://www.annasheffield.com/products/bea-arrow-ring-blackened-rutilated-quartz-black-diamonds

Very similar in look. Gorgeous brooch.

gee the price of that kinda shocked me for a piece of quartz

 

[Garry H (Cut Nut)]

Rutile needles are always dead straight - never curved.
I suspect there is ink lines on the mirror back or foil behind the stones - a decent swish around in alcohol or methylated spirits may get rid of them.
The stones do not appear to be diamond.
One simple test is to draw on a diamond with an ink or fine felt tipped pen. If the line holds then it is not a diamond.
Because diamond has the highest surface tension most inks will bead on the surface.
It is possible someone was considering buying the piece and drew on the top surface of the stones to test if they are diamonds.
It should easily wash off the glass or quartz.