Most vermiculite will have something on the back of the packaging just like soil will... It'll say pretty much what's in it... Just make double-ly sure that it DOES NOT have fertilizer in it, or it will kill your snakes.

I can't honestly say that I've seen gold vermiculite, before... But in all honesty, if I was stuck in your shoes, without a positive answer... I wouldn't touch it. If I wasn't sure it was healthy for my snakes' eggs, and I couldn't find a definite answer from someone, then I wouldn't DARE touch it, and just spend an extra twenty on something I know that works, and is effective...