Large Antique Hand Carved Italian Shell Cameo Brooch Pendant F290

This is a fairly large cameo, It measures about 1.75 Inches; Width: 1.5 Inches. It is in really nice shape. It has a pin and a fold down pendant bail so it can be worn as a brooch or pendant.  In terms of dating. It is a bit of an educated guess but there are some clues. The subject features a soft, loosely swept-up "Gibson Girl" style. Updos were common in the 1910s, transitioning into the softer, wavy bobbed styles popular in the 1920s. The profile is elegant and realistic rather than stylized or modern. She wears a large, detailed flower tucking behind her ear/hair and another resting at her neckline—a recurring motif in early 20th-century Italian shell carvings. The carving displays clean, crisp relief contrast against the light orange/brown helmet shell substrate, typical of Italian (specifically Torre del Greco) cameo carving from this era. In terms of the setting, fold down bails were common in the 1910-1920 era, and so was that filigree scroll work. Looking at the pin we can see a couple of things, one that it protrudes beyond the catch a bit, pins from the 1800's stuck way out, as the catch got more refined they got shorter and this seems like something in transition. The catch itself is a safety catch, a lock folds over the pin, however unlike modern catches the pin does not enter from the bottom it enters directly the way it is laying. Again a transition. By 1930 the locking safety catch had become what we all know, where the pin enters from the bottom of the catch. Hence. I am going to say all those things point us to a date of 1910-1920. In terms of what the metal is. It is not marked so this is a educated guess. I suppose it could be brass but I think it would be much darker by now.  Gold filled was very common and most of the cameos I see are indeed gold filled.  The reason it might not have a mark is that was not a requirement till the 1930's stamp act. Many GF items went unmarked, The other possibility is that it is plated or gilt. I actually do not think it is plated I think it is gold filled. I base that on years of selling plated jewelry. Plating is not forever, it wears off . It doesn't seem like you would use plating on a cameo this nice. You look at that bezel and ask yourself is that a 100 year old plated item? I say no. It is gold filled in my opinion.