Out of the Blue was Nathalie Verdeille's first Blue Book — her opening statement as chief artistic officer, organized around the ocean that Schlumberger had explored throughout his career. The collection descended into the depths: sea creatures, coral formations, bioluminescent forms rendered in exceptional diamonds and colored stones. Verdeille described it as an act of "contemplation, admission, respect" — a first encounter with the archive of a designer whose formal language she was still discovering. It established the methodology that the Blue Book collections would follow: begin with Schlumberger, immerse in the source, then produce something he could not have made, with the tools and confidence that the twenty-first century provides.

Tiffany Céleste — presented in 2024 — traveled in the opposite direction from Out of the Blue: from the ocean floor to the cosmos. Six chapters, each organized around a specific celestial reference from Schlumberger's repertoire. The Arrow chapter featured custom-cut stones mimicking the triangular formation of an arrowhead, around unenhanced Colombian emeralds of exceptional quality. The Apollo chapter reinterpreted Schlumberger's 1941 Trophée de Vaillance brooch with gold spikes apparently floating through continuous pavé diamonds — a new setting technique developed specifically for this piece. The collection's centerpiece was a winged Pegasus necklace in platinum and yellow gold centered on a diamond exceeding twenty carats, its feathers realized through a new feather-setting method that Verdeille's ateliers had never previously attempted. Each piece modeled up to four times in prototype before the final execution.

Sea of Wonder — presented in New York in April 2025 — returned to the ocean, but with the maturity that three years inside the Schlumberger archive had produced. Where Out of the Blue was contemplative, Sea of Wonder was technically decisive. The Urchin suite deployed paillonné enameling — a 19th-century technique that Schlumberger revitalized in the 1960s — encapsulating thin curved silver leaves between layers of enamel to create volume, texture, and new shades of color that respond to light as the ocean responds to it. The Anemone necklace centered three unenhanced Mozambican rubies totaling nearly five carats within sculptural gold accents and diamonds. The Wave necklace evoked a crashing wave through blue cuprian elbaite tourmalines of over seventeen carats. The Mermaid brooch placed a black opal exceeding ten carats at the fin of a figure in motion. Sea of Wonder's fall expression debuted in Milan in September 2025 — closing a full year of Blue Book presentation across two hemispheres.

Bird on a Rock — Schlumberger's 1965 design, in which a sculptural gold bird perches atop an exceptional gemstone as though it has landed there between one moment and the next — is the piece that most completely captures his conviction about what jewelry should be. Organic. Unpredictable. As though it had happened, rather than been made. The design has been reinterpreted in emeralds, rubellites, sapphires, and opals in the current Blue Book collections — each stone a different character, each bird a different posture, each piece a singular encounter between a craftsman and a gemstone of sufficient presence to deserve a companion. Robert Downey Jr. wore an archival Schlumberger brooch to the 2025 Academy Awards. The gesture confirmed what Tiffany has always known: the Schlumberger vocabulary is not restricted to a single generation, a single gender, or a single occasion.

The Tiffany Yellow Diamond — 128.54 carats, discovered in the Kimberley mines of South Africa in 1877 and purchased the following year by Charles Lewis Tiffany — is the fixed point around which the entire Tiffany haute joaillerie identity orbits. It has been worn publicly by four women in its history: Mary Whitehouse in 1957, Audrey Hepburn during the Breakfast at Tiffany's promotion in 1961, Lady Gaga at the 2019 Academy Awards, and Beyoncé in the 2021 campaign. It is kept on permanent display at The Landmark. It is not for sale. Its presence in the building is not a commercial proposition. It is a statement about what diamonds can be — and about the house's conviction that the most significant stone it has ever held should remain accessible to anyone who walks through the revolving doors.

Tiffany's diamond portfolio is the foundation of its haute joaillerie — an inventory of white, yellow, and fancy-color diamonds that the house describes as unlike any other in the industry. Nearly five thousand skilled artisans cut Tiffany diamonds and craft jewelry in the house's own workshops, maintaining the standard of quality that Charles Lewis Tiffany established in the 1870s when he published the first systematic guide to diamond grading — a document that preceded the GIA's standardized system by decades. Each Blue Book collection is built from this portfolio outward: Verdeille begins with the stones available, identifies which are exceptional enough to anchor a chapter, and designs from the stone's particular character rather than toward a predetermined formal result. The approach mirrors Schlumberger's own: the stone first, always the stone, with the design following from what the stone already is.