The subject item is best identified as Victorian Scottish Pebble Jewelry Brooch, St. Andrew's Cross & Crown, Mid-Victorian, c. 1860–1880, Scotland, likely Edinburgh or Glasgow. Local Scottish lapidaries, and later outsourced workshops in Birmingham and Idar-Oberstein, crafted these romantic mementos to satisfy the booming Victorian tourist trade. Queen Victoria's 1848 lease and subsequent purchase of Balmoral Castle ignited a British obsession with the Scottish Highlands, transforming local geology into high fashion. The value of pebble jewelry relies on masterfully hand-cut agates and jaspers, flush-set without visible prongs into engraved metal frameworks. This brooch embodies the 19th-century 'Highlandism' movement, where rugged Scottish motifs like the St. Andrew's Cross were refined into sophisticated Victorian status symbols.

The market for Scottish Pebble jewelry is heavily anchored by verified silver-tone metal (untested) examples, such as the Lyon & Turnbull cross ($450) and a Flying Tiger Antiques exact motif match ($575 retail). Because the subject item features an untested metal frame, these tested silver-tone comparables establish a market ceiling rather than a direct midpoint. The unsigned nature of the piece is standard for the category and does not incur a penalty, but unverified metal status significantly tempers auction expectations. If physical inspection confirms base metal (such as pinchbeck or tin alloys) rather than precious metal, the piece would perform closer to the lower end of the estimate. Value is ultimately driven by the lapidary craftsmanship, the highly desirable crown-surmounted Saltire motif, and the preservation of the original flush-set stones.