ForMatter/Materials/metal/Platinum 900 / Iridium 100
mat_platinum_pt900_iridium

Platinum 900 / Iridium 100

precious metal alloy, hard-tempered platinum · Pt900, Pt-Ir 90/10, iridium-platinum
mediumlast updated 2026-07-12

Platinum stiffened by 10% iridium — the alloy stone-setters historically chose when they needed prongs that wouldn't move under decades of wear. Slightly cooler in color than Pt950, harder, and more demanding to fabricate. Common in older platinum work; less common in contemporary U.S. jewelry, where Pt950-Ru has displaced it on cost.

Pt 90.0 / Ir 10.0 nominal. Iridium dissolves into platinum substitutionally, raising hardness by ~30% over Pt950-Ru without changing the FCC matrix. Liquidus ~1800 °C. Vickers ~175 HV in jewelry temper. The Japanese and European hallmark .900 standard; in the U.S. requires marking as Pt 90 Ir 10 to comply with FTC precious-metal labeling.

Mechanical

  • tensile strength (annealed) · MPa460
  • hardness Vickers (annealed)175
  • hardness Vickers (cold worked)280
  • density · kg/m³21540
source: Platinum Guild International technical reference

Thermal

  • liquidus · °C1800
  • solidus · °C1780
source: PGI technical bulletin

Sustainability

  • embodied carbon · kg CO₂e/kg36000
  • embodied carbon recycled · kg CO₂e/kg1300
  • recyclabilityvery high — refiner-recoverable
  • biodegradableFalse
  • certificationsLBMA / RJC / Fairmined applicable to source bullion
source: Editorial 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.
visual
neutral cool white, indistinguishable from Pt950 to the naked eye
tactile
noticeably stiffer than Pt950 in stock that's been worked, holds prongs without spring-back

PBR starter values

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

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

# finish:                   metallic
albedo                      #cdced3
metallic                    1.00
roughness                   0.25
ior                         1.45
transmission                0.00
clearcoat                   0.00
sheen                       0.00
anisotropic                 0.00
copy as JSON 
{
  "albedo": "#cdced3",
  "metallic": 1.0,
  "roughness": 0.25,
  "ior": 1.45,
  "transmission": 0.0,
  "clearcoat": 0.0,
  "sheen": 0.0,
  "anisotropic": 0.0
}
Blender 4.x Python 
# Blender 4.x — Principled BSDF
# Platinum 900 / Iridium 100 · finish: metallic
import bpy
mat = bpy.data.materials.new(name="mat_platinum_pt900_iridium")
mat.use_nodes = True
bsdf = mat.node_tree.nodes["Principled BSDF"]
bsdf.inputs["Base Color"].default_value         = (0.6105, 0.6172, 0.6514, 1.0)
bsdf.inputs["Metallic"].default_value           = 1.000
bsdf.inputs["Roughness"].default_value          = 0.250
bsdf.inputs["IOR"].default_value                = 1.450
bsdf.inputs["Transmission Weight"].default_value = 0.000
bsdf.inputs["Coat Weight"].default_value        = 0.000
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
# Platinum 900 / Iridium 100 · finish: metallic
# Run from Window → Scripting Console
import lux
mat = lux.createMaterial(name="mat_platinum_pt900_iridium", materialType="Generic")
mat.setProperty("diffuse",      (205, 206, 211))   # 8-bit sRGB
mat.setProperty("metallic",     1.000)
mat.setProperty("roughness",    0.250)
mat.setProperty("indexOfRefraction", 1.450)
mat.setProperty("transparency", 0.000)
mat.setProperty("coatingWeight", 0.000)
Substance pbrMetalRough 
{
  "_format": "Substance Designer / Painter \u2014 pbrMetalRough constants",
  "_about": "Platinum 900 / Iridium 100 \u00b7 finish: metallic",
  "baseColor": {
    "r": 0.6105,
    "g": 0.6172,
    "b": 0.6514
  },
  "metallic": 1.0,
  "roughness": 0.25,
  "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_platinum_pt900_iridium",
      "pbrMetallicRoughness": {
        "baseColorFactor": [
          0.6105,
          0.6172,
          0.6514,
          1.0
        ],
        "metallicFactor": 1.0,
        "roughnessFactor": 0.25
      },
      "extensions": {
        "KHR_materials_ior": {
          "ior": 1.45
        }
      }
    }
  ]
}
USD Preview Surface 
# USD Preview Surface — UsdShade.MaterialLook prim attributes
# Platinum 900 / Iridium 100 · finish: metallic
def Material "mat_platinum_pt900_iridium" {
    token outputs:surface.connect = </mat_platinum_pt900_iridium/PreviewSurface.outputs:surface>

    def Shader "PreviewSurface" {
        uniform token info:id = "UsdPreviewSurface"
        color3f inputs:diffuseColor = (0.6105, 0.6172, 0.6514)
        float   inputs:metallic     = 1.000
        float   inputs:roughness    = 0.250
        float   inputs:ior          = 1.450
        float   inputs:opacity      = 1.000
        float   inputs:clearcoat    = 0.000
        token   outputs:surface
    }
}
↓ download glTF material
ProcessBrazing · Laser Cutting · CNC Milling
Substitutes
Platinum 950 (Pt950)
Palladium 950 (Pd950)

Second life

repairabilityvery high — iridium-hardened platinum welds and forms with platinum bench discipline; the European fine-jewelry workshop standard.
recyclabilityvery high — PGM refiner; iridium content adds to the recovery value.
disposal pathspecialty PGM refiner.
typical longevity500 years (typical)
failure modes
  • surface-pitting from inattentive high-temperature work
  • iridium segregation in thick castings (rare; metallurgical control issue)

Platinum Guild International technical literature; Stuller Pt900 specifications.

Citations

Further reading