This is not corundum pseudomorph after spinel, it's just spinel (with a minute epitactic xls of hogbomite group.)
The corundum ps spinel crystals are quite distinctive, with weird pebbly surfaces, and a greyish color, nothing like the sharp, clean spinel, black to the naked eye, dark green with magnification, shown here.
I hope to soon have more info on this locality, and perhaps more on the hogbomite.
The Corundum is here. The slightly greenish top to the Spinel crystal on the upper right side of the sample is Corundum. This is one of the few samples I have seen frm here that is in the process of transformation so the crystals are partially Spinel and partially Corundum pseudomorphs. I will post a child photo of a close-up on these compound crystals. I am glad to see you will have data on the Hogbomite as I have been curious where it fits in that group.