Why do shallow cut side stones get dirty so fast!?

[Lakefront]

Can someone please tell me why, oh why, do shallow cut side stones like traps, half moons and cadillacs seem to get dirty so quickly?
They are the most high maintenance stones for me. I clean them just as much as other shapes but they seem to build up grime much quicker than even an emerald cut. Why is this?

 

[tyty333]

I think round brilliants have so much better light return than fancy cut stones that they can still manage to sparkle with some
grime on them. Fancy cut stones...no bueno with any grim.

Or, was this meant to be a rhetorical question?

 

[Garry H (Cut Nut)]

Can someone please tell me why, oh why, do shallow cut side stones like traps, half moons and cadillacs seem to get dirty so quickly?
They are the most high maintenance stones for me. I clean them just as much as other shapes but they seem to build up grime much quicker than even an emerald cut. Why is this?

Because they are very shallow. Shallow round diamonds show a fraction of the dirt that Tolkowsky or the deepest GIA XXX show - but we are talking deviations of less than half a degree from the supe doopa best proportions for shallow diamonds that show less dirt.
Some of the stones you mention are 10 to 20 degrees shallower than ideal.
So when light hits a dirty pavilion the grime makes the effective pavilion angle about the same as quartz or aquamarine. So you get a classic window effect and all you see is the grime.

 

[Lakefront]

Thanks! I guess I’ll just have to be super vigilant about keeping them clean.