ForMatter/Materials/metal/Niobium (Pure)
mat_niobium_pure

Niobium (Pure)

refractory metal, anodizable · Nb, columbium (historical)

A refractory metal — high-melting, corrosion-proof, biocompatible — best known in jewelry because it accepts color the way titanium does, only more vividly. Run a low voltage through a niobium piece in an electrolyte bath and a transparent oxide layer grows on the surface; the layer's thickness sets which wavelengths interfere, which sets the color. The whole rainbow is voltage-mapped. No dye.

BCC structure, density 8.57 g/cm³, melting point 2477 °C — among the highest-melting metals in commercial use. Hypoallergenic, non-reactive across biological environments, and electrolytically anodizable in saturated salt solutions across 0–120 V to produce structurally-colored Nb₂O₅ films from gold (~10 V) through blue (~30 V) violet (~60 V) green (~80 V) to magenta (~100 V). Hardness modest (Vickers ~80 HV annealed) — niobium pieces are often relatively thick to compensate.

mechanical

  • tensile_strength_mpa_annealed275
  • yield_strength_mpa_annealed170
  • hardness_vickers_annealed80
  • density_kg_m38570
source: ASM Handbook Vol. 2; Reactive Metals International datasheet

thermal

  • melting_point_c2477
  • thermal_conductivity_w_mk53
source: CRC Handbook

Sustainability

  • embodied carbon kg co2e per kg47
  • sourceEditorial estimate from ICE / Granta CES EduPack class databases — industry mean, with cradle-to-gate boundary unless otherwise noted. Embodied carbon for any specific product depends on supplier mix, recycled content, and energy grid; verify against a primary source before using these numbers in a sustainability claim.
  • recyclabilitymoderate — recoverable via specialty refiners; jewelry-scale recycling rare
  • biodegradableFalse
  • certificationsASTM F1295 (medical-grade niobium for implants)
  • localityprimary mining concentrated in Brazil (CBMM) and Canada
visual
silver-gray as polished, vividly anodizable across the visible spectrum without dye
tactile
harder under the hand than gold, softer than steel, takes a smooth polish
weight perception
moderate

PBR starter values

finish · iridescent — open for table, JSON, host snippets, downloads

Principled BSDF defaults derived from the sphere iridescent finish. Reasonable seed for Blender, Substance, Keyshot, Rhino — tune per material. Or grab the whole library at once: ForMaterials library →

# finish:                   iridescent
albedo                      #2050a0
metallic                    0.30
roughness                   0.20
ior                         1.45
transmission                0.00
clearcoat                   0.60
sheen                       0.00
anisotropic                 0.00
iridescence                 1.00
iridescence_ior             1.30
iridescence_thickness_min   100
iridescence_thickness_max   800
thickness                   0.60
attenuation_distance        0.40
emissive_intensity          0.07
copy as JSON
{
  "albedo": "#2050a0",
  "metallic": 0.3,
  "roughness": 0.2,
  "ior": 1.45,
  "transmission": 0.0,
  "clearcoat": 0.6,
  "sheen": 0.0,
  "anisotropic": 0.0,
  "iridescence": 1.0,
  "iridescence_ior": 1.3,
  "iridescence_thickness_min": 100,
  "iridescence_thickness_max": 800,
  "thickness": 0.6,
  "attenuation_distance": 0.4,
  "emissive_intensity": 0.07
}
Blender 4.x Python
# Blender 4.x — Principled BSDF
# Niobium (Pure) · finish: iridescent
import bpy
mat = bpy.data.materials.new(name="mat_niobium_pure")
mat.use_nodes = True
bsdf = mat.node_tree.nodes["Principled BSDF"]
bsdf.inputs["Base Color"].default_value         = (0.0144, 0.0802, 0.3515, 1.0)
bsdf.inputs["Metallic"].default_value           = 0.300
bsdf.inputs["Roughness"].default_value          = 0.200
bsdf.inputs["IOR"].default_value                = 1.450
bsdf.inputs["Transmission Weight"].default_value = 0.000
bsdf.inputs["Coat Weight"].default_value        = 0.600
bsdf.inputs["Sheen Weight"].default_value       = 0.000
bsdf.inputs["Anisotropic"].default_value        = 0.000
KeyShot Python (lux)
# KeyShot 11+ — lux Python API, Generic material
# Niobium (Pure) · finish: iridescent
# Run from Window → Scripting Console
import lux
mat = lux.createMaterial(name="mat_niobium_pure", materialType="Generic")
mat.setProperty("diffuse",      (32, 80, 160))   # 8-bit sRGB
mat.setProperty("metallic",     0.300)
mat.setProperty("roughness",    0.200)
mat.setProperty("indexOfRefraction", 1.450)
mat.setProperty("transparency", 0.000)
mat.setProperty("coatingWeight", 0.600)
Substance pbrMetalRough
{
  "_format": "Substance Designer / Painter \u2014 pbrMetalRough constants",
  "_about": "Niobium (Pure) \u00b7 finish: iridescent",
  "baseColor": {
    "r": 0.0144,
    "g": 0.0802,
    "b": 0.3515
  },
  "metallic": 0.3,
  "roughness": 0.2,
  "ior": 1.45,
  "opacity": 1.0,
  "anisotropyLevel": 0.0,
  "_notes": "Channels listed are the standard Substance pbrMetalRough output. Drop into a Uniform Color node per channel, or as the constant input on a layered stack."
}
glTF 2.0 Metallic-Roughness
{
  "asset": {
    "version": "2.0",
    "generator": "ForMatter"
  },
  "materials": [
    {
      "name": "mat_niobium_pure",
      "pbrMetallicRoughness": {
        "baseColorFactor": [
          0.0144,
          0.0802,
          0.3515,
          1.0
        ],
        "metallicFactor": 0.3,
        "roughnessFactor": 0.2
      },
      "extensions": {
        "KHR_materials_ior": {
          "ior": 1.45
        },
        "KHR_materials_clearcoat": {
          "clearcoatFactor": 0.6
        },
        "KHR_materials_iridescence": {
          "iridescenceFactor": 1.0,
          "iridescenceIor": 1.3,
          "iridescenceThicknessMinimum": 100,
          "iridescenceThicknessMaximum": 800
        }
      }
    }
  ]
}
USD Preview Surface
# USD Preview Surface — UsdShade.MaterialLook prim attributes
# Niobium (Pure) · finish: iridescent
def Material "mat_niobium_pure" {
    token outputs:surface.connect = </mat_niobium_pure/PreviewSurface.outputs:surface>

    def Shader "PreviewSurface" {
        uniform token info:id = "UsdPreviewSurface"
        color3f inputs:diffuseColor = (0.0144, 0.0802, 0.3515)
        float   inputs:metallic     = 0.300
        float   inputs:roughness    = 0.200
        float   inputs:ior          = 1.450
        float   inputs:opacity      = 1.000
        float   inputs:clearcoat    = 0.600
        token   outputs:surface
    }
}
↓ download glTF material
Finishes that suit this material

Second life

repairabilitymoderate — niobium welds in inert atmosphere (similar discipline to titanium); the favored anodize-color metal in art jewelry.
recyclabilitymoderate — small-volume specialty recycling.
disposal pathspecialty refractory-metals recycler.
typical longevity100 years (typical)
failure modes
  • oxide-color wear at high-contact surfaces
  • hydrogen embrittlement at sustained stress

ASM Handbook Vol. 2: Refractory Metals; Reactive Metals International niobium technical literature.

In the collection

  • Smithsonian American Art Museum
    Brooch 348.2, Zack Peabody · 1998

    Fabricated and cold-connected stainless steel, niobium, titanium, plated base metal. Accession 1999.11A-C. Threaded-rod cold connections instead of solder; niobium reads here as the warm-gray third tone alongside the cooler stainless and titanium.

Citations