It's all unusual because it is uncharted territory. My guess would be assuming that it all pans out that this is due to various impurities and that it will take a while before we have a sample that is pure enough that all of these properties can be nailed down for good.
What's strange is that drop at higher temps, that's either a measurement anomaly or something really odd.
What's strange is that drop at higher temps, that's either a measurement anomaly or something really odd.