Busy reading on these issues so, I just made time to respond. It does appear to me that ImageJ has plenty of computational power to improve both my effort to identify individual particles, increase particle count with fewer samples and make all of this more efficient and robust. I am attaching three representatives *.tiff for you to comment on.
I uploaded “Img10” to provide indications of what particles are shaped like and their overlap characteristics to make these issues less ambiguous. The other two images are more likely to be encountered by searching on the grid (3 mm Formvar coated copper). However, if you take the ideas these three images provide and let your mind take them to their logical extent you will obtain the result shown below, albeit at lower magnification resulting from the larger size of the conglomerate.
In my reading since posting the initial question it appears these samples may challenge segmentation algorithms. I consider it a welcome opportunity if this has placed me into a situation requiring further development of ImageJ, the Trainable Weka Segmentation, etc. I am all in! This is what we live for….
Edit - In “proofing” response after finalizing it I cannot “see” images despite no indication to the contrary when uploading these. What do I need to do to correct this? It appears my method of attaching images is fine - one of the (4) methods known to work or be regarded as acceptable.