Crimson & Navy & Gray

Crimson is the pyrite inclusion — the deep vivid crimson of the oxidized iron pyrite crystals in Chilean lapis lazuli. Lapis lazuli geology: lapis lazuli (from Latin: lapis — 'stone' + lazuli — from Medieval Latin: lazulum — from Arabic: لازورد — lāzaward — from Persian: لاژورد — lāzhward — 'blue stone') is not a single mineral but a metamorphic rock composed primarily of: lazurite (Na₃Ca(Al₃Si₃O₁₂)S — a feldspathoid mineral — typically comprising 25-40% of the rock — the primary blue mineral — producing the characteristic intense blue color through the inclusion of sulfur radical anions — the most rare and the most structurally specific blue mineral in the Earth's crust); pyrite (FeS₂ — 'fool's gold' — appearing as small golden cubic crystals scattered throughout the lazurite matrix — the most immediately visually striking and the most decoratively desirable inclusion in lapis — the specific pyrite crystals oxidizing at their surfaces to produce the characteristic golden-to-crimson-to-bronze coloration that is the most immediately distinctive feature of the highest-quality lapis lazuli). The Chilean source: the most important lapis lazuli source in South America — and the second or third most important source in the world — is the Flor de los Andes mine in the Coquimbo Region of Chile (in the Cordillera of the Andes — at altitudes of approximately 3,500-4,000 meters — the most mineralogically productive lapis lazuli zone in the western hemisphere). Chilean lapis characteristics: Chilean lapis typically has the most vivid and the most saturated blue color, with the most prominently visible pyrite inclusions (the specific oxidized pyrite crystals producing the most characteristic golden-to-crimson stippling pattern that the most knowledgeable collectors and the most experienced jewelers associate most immediately with Chilean provenance — as opposed to Afghan lapis, which tends to have less visible pyrite and the most uniformly deep blue color). Navy is the Atacama sky — the very deep dark navy of the Atacama Desert night sky. The Atacama Desert: the Atacama Desert (the most arid non-polar desert on Earth — a plateau in South America covering approximately 105,000 km² — located in northern Chile between the Pacific Coast Range and the Andes — receiving on average less than 1 mm of rainfall per year in the most arid core regions — with some specific meteorological stations recording zero precipitation over periods of decades) is the most astronomically pristine location on the inhabited Earth. Astronomical facilities: the European Southern Observatory (ESO — the most important international astronomical organization in the world — with its most important observatories all located in the Atacama Desert): the Very Large Telescope (VLT — Cerro Paranal — 2,635 meters altitude — the world's most productive ground-based telescope facility — consisting of four 8.2-meter Unit Telescopes and four 1.8-meter Auxiliary Telescopes — together constituting the most powerful optical telescope system in the world); ALMA (Atacama Large Millimeter/submillimeter Array — the most powerful radio telescope in the world for studying star formation and galaxy evolution — 5,058 meters altitude — the most extreme altitude of any major radio telescope facility); and the ELT (Extremely Large Telescope — under construction on Cerro Armazones — 39.3-meter primary mirror — the largest optical/infrared telescope ever built — the most ambitious single ground-based telescope project in the history of astronomy). Gray is the calcite matrix — the medium neutral gray of the silicate host rock. Lapis matrix minerals: the non-blue components of lapis lazuli (the matrix or gangue minerals that make up the rock surrounding the blue lazurite) include: calcite (CaCO₃ — the most abundant — appearing as white to pale gray veins and patches — the most immediately contrastingly visible against the vivid blue lazurite); sodalite (Na₄Al₃Si₃O₁₂Cl — a pale blue to gray feldspathoid — the most structurally similar to lazurite — often indistinguishable from pale lazurite to the naked eye); and diopside (CaMgSi₂O₆ — a pyroxene — appearing as medium to dark gray mineral grains throughout the matrix). The specific gray: the combined visual effect of the calcite and silicate matrix minerals in the most typical Chilean lapis lazuli sample is a medium, slightly warm neutral gray — the specific gray that surrounds and contrasts with the most vivid blue lazurite and the most golden-to-crimson pyrite crystals.