Until it's actually revealed in canon what the heck that bubbled gem inside Lion's mane is, fans are going to speculate. But here's a vastly different theory than what I usually come across. The fandom has widely accepted that the gem is Bismuth, based on its appearance. But what if it's not? What if it's an entirely different gem? Check out the theory below for a new spin on the mystery gem in Lion's mane.
Pictured above is a gem many in the fandom quickly took to calling bismuth, but what if that’s not quite correct. According to wikipedia:
What if Bismuth is actually an artificial Rose Quartz?
Of course, lab grown quartz hoppers don’t actually look like this (google it if you like). They are much less photogenic, and not as easily distinguished from normal crystals, but given that SU is a very stylized cartoon it’s possible the artists drew it differently in order to make it look nicer and also more bizarre to emphasize it’s artificial nature?
It’s also worth noting that despite it’s bismuth-like appearance, this gem actually is pink. It’s not just the shading of the bubble either, Other bubbled objects aren’t recolored:
According to The Guide to the Crystal Gems, Rose did have the desire to be a mother. Given that having Steven and giving up her physical form was less than an idea situation for her, she may have attempted to create a child artificially at first. At some point, “bismuth” must have become corrupted, it may have even happened automatically due to the unstable nature of an artificial gem. in this case, Rose would have left “bismuth” behind for Steven because it was practically his half-brother!
However, this theory has some ambiguous points to it. This gem couldn’t have been made from rose herself since the writers clarified that every part of her went into Steven. Gems themselves don’t seem to form that way, though it’s possible that this gem may have been created in a manner similar to a pearl, who also are not created in a traditional manner.
Of course this still leaves questions, but the one most important to the story is “does this gem age?” Gems are born fully-formed and self-aware. If Rose wanted to be a mother, something like this would likely be out of the question. But in her case this might have been avoidable even without a biological component from Greg
Rose’s powers revolve around life and growth, and not only for organic life. Steven’s spit and Rose’s tears heal both biological and geological injuries. She can grow plant life naturally and modify it at her whims, creating sentient plant life like the Magic Moss and Watermelon Stevens. Who says she couldn’t do the same for gems as well, and from a seed crystal generate a gem that ages and develops outside of the ground?
Of course, all of this is speculative. We can’t be sure what the gem in the bubble is like, or even if it’s a rose quartz at all. Only time will tell what the gem in the bubble really is