Han Blue (BaCuSi₄O₁₀)

Synthetic Inorganic Pigment Powder

Han Blue is a historically significant synthetic inorganic pigment defined by its crystal structure rather than its provenance. Chemically, it is a barium copper silicate (BaCuSi₄O₁₀) with a layered silicate framework that produces a deep, stable blue through lattice-scale electronic structure rather than molecular dyes or chromophores.

This pigment is supplied as a dry, unbound powder and contains no binders, extenders, or additives.

Material & Structure

Han Blue contains square-planar Cu²⁺ centers embedded within a rigid Si₄O₁₀ silicate lattice. Its color arises from crystal-field splitting and long-range internal electric fields generated by the crystal as a whole, shifting electronic transitions relative to simpler copper oxides or silicates.

Beyond color, Han Blue exhibits anisotropic solid-state behaviors associated with its layered architecture. Experimental studies report negative thermal expansion within the silicate planes over broad temperature ranges, low thermal conductivity dominated by phonon scattering, and subtle low-temperature structural transitions that reduce crystallographic symmetry without disrupting the lattice.

The result is a pigment whose optical and physical properties are governed by extended crystal structure, not surface chemistry.

Historical Context

Han Blue was synthesized in China during the late Zhou and Han periods using high-temperature kiln processes and mineral precursors. It represents one of the earliest known examples of deliberate, repeatable pigment synthesis, produced alongside related copper silicate pigments including Han Purple.

Its rediscovery in modern analytical research reflects continuity in material performance rather than the recovery of a lost technique.

Production Philosophy

Elemental Color produces pigments in small batches using high-purity inorganic reagents and tightly controlled thermal processes. Our synthesis approach emphasizes material fidelity and structural correctness over cosmetic uniformity.

Batch-specific synthesis and characterization data are maintained by the manufacturer and made publicly available.

Details

• Composition: Barium copper silicate (BaCuSi₄O₁₀)

• Form: Dry inorganic pigment powder

• Net weight: 2oz-1lb

• Batch size: Small-batch production

• Country of origin: United States

Intended Use

Suitable for professional artists, researchers, fabricators, conservators, and others experienced with dry inorganic pigments. Han Blue may be incorporated into paints, inks, glazes, composites, or experimental materials using appropriate binders and methods.

Important Notes

• Supplied as a raw pigment only; no binders, extenders, or additives included

• Not a food, cosmetic, or consumer coating; not for human or animal consumption

• No claims are made regarding fitness for any specific application

• Handle using standard professional precautions for fine powders

• No canonical SDS exists for Han Blue; a research materials safety brief is available upon request