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Will do. Once the kami form Charlie gets here I will message you and bring the yellow rocks with me :)

I dont think it makes a difference. Yeah when I tried it one of mine turned white against black background when dry as well.
Then I picked a BD on eBay and the slurry does indeed look different....

I think Hazitcho posted this trick. Make slurry with diamond plate. Let it dry. If the slurry dries white then it's light green, if yellowish then yellow green.
Nice find :)