Factual error: The geodes occurring in the mantle during the film are impossible in two ways. Firstly, there are no gaps at those depths. The pressure is approximately 3.5 million times surface pressure, and it is not feasible that such structures could form, let alone be maintained. Secondly, the crystals inside the geodes are described as amethysts. Amethysts are a purple variety of quartz, and as any undergrad geology student could tell you, there is no quartz in the mantle, it simply is not stable at such high temperatures.
Plot hole: When the crew's vessel gets stuck in the giant geode and the crystal jams the 'impeller', the magma begins to fill the chamber. They see it melting the crystals, yet they frantically continue working to free the crystal from the impeller and lose a crewman...and yet when they get back in the vessel, the magma indeed melts out the crystal that jammed the impeller. With 2 geologists onboard you would think they'd know that.
Question: Why does General Purcell want Virgil to fail? It seems all he's trying to do is stop them from achieving their goal. He knows full well DESTINI stopped the core in the first place and is determined to fire it again with Virgil down there, knowing they will die. Why would he want Earth to die?Brad