100% Pelt Nova, size should be around 7/8ths & up, usually bigger, surface fractures are common among this type, but ones w/o can be found. Can come in a few colors. Here's mine, no fractures, yes it took a while to find. The whitish ribbons like yours seem to be most common.
Here's a link for ya to check out on them & their same day run partners.
LINK :: https://www.allaboutmarbles.com/viewtopic.php?f=5&t=38379&p=283233&hilit=peltier+novas#p283233