{"reference": {"slug": "greubel-forsey-gf02n", "brand": "Greubel Forsey", "ref": "GF02N", "model": "Invention Piece 1", "case_material": "18k White Gold", "provenance": "extracted_from_auction_comps", "url": "https://mostexpensivewatches.net/reference/greubel-forsey-gf02n", "description": "The Greubel Forsey Invention Piece 1 (GF02N) in 18k white gold was introduced in 2007 as a limited edition of 11 pieces, marking the first entry in a series dedicated to the brand’s fundamental technical breakthroughs. This reference showcases the Double Tourbillon 30° movement, featuring an inner cage inclined at 30 degrees rotating every minute inside a four-minute outer cage. The dial architecture omits traditional hands, utilizing two concentric rotating disks for hours and minutes positioned over a large frosted bridge. Collectors value this reference for its historical significance as the inaugural Invention Piece and its extreme rarity, with only 33 total units produced across three metals. On the secondary market, these timepieces typically command prices in the mid-to-high six-figure range. A notable auction result occurred in 2021 when a white gold example sold for approximately $450,000."}, "listing_stats": {"count": 0, "median": 0, "low": 0, "high": 0}, "listings": [], "auction_lots": [{"slug": "greubel-forsey-gf02n-2021", "brand": "Greubel Forsey", "reference": "GF02N", "model": "Invention Piece 1", "case_material": "18k White Gold", "hammer_usd": 400000, "year_sold": 2021, "venue": "Christie's Hong Kong", "lot_summary": "A white gold example of the Invention Piece 1, which pays tribute to the brand's foundational Double Tourbillon 30° invention.", "source_url": "https://www.christies.com/en/lot/lot-6483904", "provenance": "ai_generated_grounded", "url": "https://mostexpensivewatches.net/auctions/greubel-forsey-gf02n-2021"}]}