its very likely that diamond orders work for more than just pearls. remember when rose told garnet no more questions? and in another episode steven was sad i think and amethyst was like "should we talk to him?" and garnet was like "You do it. you know i cant ask questions"

OH YEAH, you’re so right i totally forgot Garnet has a weird inability to ask questions ‘cause of Rose, haha. So yeah that shows it can affect non-Pearl gems too! 

also that made me look back on the clip from The Answer, because now im in deep wondering about this shit, and had the thought that maybe a specific something has to be done to make it an official Order…? And I thought I remembered Rose taking Garnet’s hands and crossing them, in the same way she does with Pearl when she tells her not to speak of their secret ever again:

(though her hands aren’t actually SHOWN holding garnet’s when she says ‘no more questions; don’t ever question this’, it is implied bc she’s already holding garnet when she says ‘you already are the answer’ in the very next shot)

so maybeeeee, there has to be a physical touch? maybe the Order has to be direct and unambiguous? we don’t know the EXACT wording Pink used with Spinel, and even if Spinel is quoting her verbatim in the song, she doesn’t hold/cross Spinel’s hands when she says it. although…

she does Boop