the world actually depends on all of the diamonds even the dark one which means if one of them get shattered, the world falls apart, so if someone manages to shatter one of them... then they are doomed... and the Dark Amethyst and the Obsidian are not the only ones that are sentient, the Diamonds are actually gods that does not look like life but the caretakers treat it like they are living and breathing but the white diamond... they worship the white diamond since that it is a super powerful diamond... and is actually super harder to shatter other than it's younger siblings which means... White Diamond's power cannot be turned off and if one of it's siblings get shattered, White will quickly repair it's siblings and sends it's wraith to anyone who caused harm to it's siblings
and yes white Diamond is almost a biblically accurate angel... ALMOST!!! because it's actually the God of Light known as Lunallix