Diamond Heist [Garnet Group] Secret Vault

[you serve zero purpose]

So a few weeks ago i played this heist with pubs, and because i just got back at this game again and wanna try some new stuff, and then there's this one player he opened a secret vault at the main vault where you supposed to be bagging all the diamonds, but he got disconnected and never joined again, and then i was wondering how to do that, so im playing it solo either in stealth or loud i still can't get the secret vault open, it's really similar to overdrill i guess...

So does anyone know the secret?? Do i have to play it in certain difficulties?? Cuzz i remember we were playing it death wish loud when that happened...

[Olivinism]

On Overkill the Red Diamond room has a 10% chance to spawn, and on Mayhem+ it is a 20% chance. (Citation needed, read from a different post a while back.)

[Seal]

Originally posted by GyRO:

On Overkill the Red Diamond room has a 10% chance to spawn, and on Mayhem+ it is a 20% chance. (Citation needed, read from a different post a while back.)

I thought it was 40%

[E3kHatena]

The back room contains the Red Diamond, and has a 10% chance to spawn on Overkill and a 20% chance to spawn on Mayhem, Death Wish, or One Down. If the door is not there when you open the vault, you would need to restart until it does. That said, aside from the achievement, the actual diamond itself isn't that valuable, being worth less than a bag of meth from Hotline Miami.