The Mystery of the eBay Image

Recently while scrolling through images on eBay, I spotted this image of mother and child. It  was labeled "Antique Tintype Daguerreotype Photograph of Mother & Child In Original Frame".  I scratched my head a bit.  Which is it? A tintype or daguerreotype?  From her clothing, I suspected she was a tintype or an ambrotype.  I prefer cased images to CDVs because of the level of detail. The price was affordable for a tintype and out of this world for a daguerreotype, so I bit.   When she arrived in the mail, I was eager to find the answer to the mystery (I think I am easily amused or excited in the covid 19 era).  She was, as I suspected, an ambrotype.  The clarity and detail of the mother were very good and the blurry baby with a hint of smile around the eyes reminded me of photographs of my own children.  

Unfortunately, many people do not know the differences between these types of early photography even at museums.  Our local history museum was very suspicious of me when I said they had a tintype mislabeled as a daguerreotype.  "How do you know? We have been told by an expert that this is a daguerreotype?" I guess the best place to start getting people to know the correct information is sharing it.  I am not a photography expert, just a collector of images, but here are some definitions to help identify types of cased images.

Daguerreotype - Positive image on silver. Introduced by Jacques Daguerre in 1839.  Expensive and labor intensive, but very high quality images.  Quickly replaced by the Ambrotype and Ferrotype in the 1850s.  Although the images are durable, tarnish to the silver plate can cause irreparable damage the image.
 
Ambrotype - Negative image on glass with black backing.  Patented in the United States in 1854.  Much cheaper process than the Daguerreotype.  Unfortunately, the images are vulnerable in comparison to daguerreotypes and ferrotypes.
 
Ferrotype - Popularly referred to as tintypes.  Negative image on iron coated with lacquer or black paint.  Invented in Ohio by Hamilton Smith in 1856.  Much less expensive and more durable than Ambrotype.  Ferrotypes did not require a case.  In the US, the ferrotype replaced the ambrotype by the end of the American Civil War.  Popularity of the ferrotype did not catch on as quickly in Europe.