Responses
Ok because of the gem thing I think is this one:
Unmei no Hana
and the part of the arranged marriage made me think about this manga:
http://www.mangago.zone/read-manga/koi_wa_maiorita/
Let me know if it was one of them.(づ￣ ³￣)づ
It was the first one that you mentioned! Thank you!!!!! ヾ(☆▽☆)
You are welcome my friend! ლ(´ڡ`ლ)
Does anyone remember this yaoi manga where they were arranged marriage and the seme was against it after finding out that his supposed bethroted is a guy (he'd seen him dressed as a girl when they were kids). And whenever they had sex, there are flowers/petals(?) everywhere but there was one time, a gem was produced after they made love. They were kind of magicians I think(?). Not sure if it was completed but there was also a rival (another uke? A rich one. With a Butler....?) who told the seme that he was his real soulmate. And unfortunate things started to happen the moment the seme and the uke (the original uke, not the rival) lived together (right after their marriage/unification)