Majestic Jr. rollerball in Rhodium & Black Titanium, with a Lava Lamp #106 blank. Sanded to 2000 grit, then polished on the lathe with Meguiar's Mirror Glaze Swirl Remover 2.0 for a matte finish. In person, it almost looks like tightly-packed shredded tobacco...
Your pen is Impeccably crafted, and looks fantastic. This is also my favorite pen kit. I have one turned in worthless wood, and acrylic, that I don't know if I will ever be able to sell.