Since I was getting all the information from the file saved in Gimp, I too suspected that it might be an issue with the creating tool, rather than IM itself. I will try getting an answer at DT forum
I have an image file processed with Daraktable. I wanted to put the timestamp on the image by extracting the exif data. I observed that the exif data extracted using the imagemagick is very limited. $ identify -format '%[exif:*]' dsc_1807.jpg exif:ImageDescription=TB Dam, Hosapete exif:Make=NIKON ...