In setting the paste, often pitch or similar sticky material was utilized to anchor the stone during setting. This black then shows through. It is thought to have mimicked the open cutlet of early diamond cuts, which often look quite dark or black.The cutlet is the bottom of the stone, where in today's modern stone cuts all the facets come to a perfect point. In years past, the facets did not meet in a point but joined around a flat area on the bottom. Black dot paste is one hallmark of very fine quality paste. These stones are beautifully hand cut. Measurements: The brooch is 43mm wide x 36mm high. Marked: No marks but tests as Sterling Silver. I can't see any chips to the stones. Condition can be subjective so I have included super size images. Please inspect them carefully as they form part of the description. About Me: I have been collecting antique jewellery for 30 years and worked in the fashion and design industry for 20 years. I now specialise in antique Victorian and Georgian jewellery but also vintage statement pieces. I have a particular interest in Mourning jewellery, early Paste, early gemstones and Diamond cuts, Turquoise, Coral, Pearls, Moonstones and Opal. Please take a look at my other listings. The item "Large Antique Georgian Sterling Silver & Closed Back Black Dot Paste Brooch" is in sale since Sunday, December 30, 2018. This item is in the category "Jewellery & Watches\Vintage & Antique Jewellery\Vintage Fine Jewellery\Pre-1837". The seller is "gerridevine" and is located in london, London. This item can be shipped worldwide.