Two Marble in One + Natural Marble Vein

[Tage]

but a trusted friend still do and he thought he'd found a 2nd deposit with bigger bonus.

I wonder who that might be...

Edit: But now he showed me some marble deposits with all bonuses, both freshly found (at the same time) .

Yes, I can confirm that.
One marble deposit in s5 and one in s8 were found at the same time (Two Marble in One).
Both of them were also 24% larger due to Natural Marble Vein
(1.24 × 360 = 446 for the one in s5 and 1.24 × 330 = 409 for the one in s8)