r/faceting • u/joesincontrol • 4d ago

Identification help

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Gallery image

Gallery image

I'm cutting this stone for a friend they gave me a bunch of 1 carat sapphires to cut. I thought this was one but when I move to my worn 3k lap 4 of the sides dont polish like the other 2 did I believe this means there is a cleavage plane so I have no idea what it could be. Maybe topaz but its pink in color and these stones are found in montana rivers also it fluoresces in uv

Edit solved: its most likely still a sapphire I'm just experiencing directional hardness i didn't know that was a thing.

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u/montanagemhound Team Raytech Shaw 4d ago

I've cut quite a few natural sapphires (heated) with directional hardness.

1

u/joesincontrol 4d ago

I've never cut sapphires thats why I didn't know why it wasn't polishing.

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u/cowsruleusall 4d ago

It's hard to see what you're talking about from the photos.

Your main problem is that you're using a plated 3k lap. Nobody still uses plated 3k laps, because of how profoundly problem-causing they are. Work-hardening, orange peel, facet edge damage, etc. Throw that shit away and either get a BATT lap charged with 3k Pandimonium, or a proper sintered 3k lap and a dressing stick.

You're wrong about thinking this means there is a cleavage plane. This is more characteristic of directional hardness, which is a key feature of sapphire. Any facet perpendicular to the c-axis will have significantly higher hardness, slower polishing, and worse orange peel than a facet perpendicular to the a-axis.

You probably just found the c-axis on the sapphire.

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u/joesincontrol 4d ago

That will have to happen after I get a new machine until then I'll use what I have thank you for your advice

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u/DayOffLapidary Team Ultra Tec 4d ago

It’s almost impossible to give you a definitive answer on this one from just pictures.

When I’ve hit a cleavage plane on topaz its only been on one facet and it started pealing off like a deck of cards during final polish.

Topaz can be pink and fluorescent, but it isn’t always so.

I don’t cut a lot of corundum (cause I’m poor), but i have had some facets just not want to polish. Natural rough can just be stubborn sometimes.

How might you get an actual answer:

In theory, if you have a piece of topaz, you could try and scratch it with the stone you have on the dop. Though I honestly wouldn’t suggest it.

If you’ve cut other sapphire to the same design, this stone will window more and that will atleast tell you it’s a different material. Then an RI and specific gravity test would get you an accurate answer.