ForMatter/Materials/stone/Limestone
mat_limestone

Limestone

sedimentary stone — calcium carbonate · calcium carbonate stone, indiana limestone, portland stone (UK quarry name)
mediumlast updated 2026-04-28
metallic 0.00
hue shift +0°

Sediment of ancient sea creatures pressed into rock. Soft enough to carve with a chisel, hard enough to clad a bank. The Empire State Building, the Pyramids' core, every Indiana courthouse — limestone. Weathers slowly to a chalkier surface; takes graffiti, takes acid rain. Cuts reveal fossils.

Sedimentary rock composed primarily of calcite and aragonite (CaCO3). Compressive strength 60–170 MPa depending on porosity and fossil content. Reacts visibly with dilute acids — a quick HCl drop on a fresh cut is the field test. Mohs hardness 3 (a copper coin scratches it). Used as cut block (dimensional stone), as crushed aggregate, and as the principal feedstock for portland cement.

mechanical

  • compressive_strength_mpa130
  • elastic_modulus_gpa35
source: Wikipedia — Limestone; building-stone literature

physical

  • density_kg_m32600
  • mohs_hardness3
source: Wikipedia

Sustainability

  • recyclabilityhigh as crushed aggregate; cut block is reusable
  • biodegradableFalse
  • certificationsANSI/NSC 373 (sustainable production of natural dimension stone)
visual
warm white to honey to pale gray, fossil-flecked at any cut
tactile
cool, slightly chalky, recognizable underfingers — softer than it looks
weight perception
very heavy
acoustic
muted thud, no ring
Jun'ichirō Tanizaki (dead — channeled)

Limestone is a material that asks for time. Cut fresh, it shows the white of every quarry — uniform, optical, a little embarrassed. Left to weather, it gathers a softer color, the same way an old hand gathers translucence. The fossil at the cut is older than every reading of it. The pleasure is in waiting for the wall to look used, and in the willingness to let the stone do that work without correction.

Channeled within the philosophy of Jun'ichirō Tanizaki, *In Praise of Shadows* (originally *In'ei Raisan*, 1933; trans. Thomas J. Harper and Edward G. Seidensticker, Leete's Island Books, 1977), motifs of patina, time, and the dignity of darkening surfaces.

PBR starter values

Principled BSDF defaults derived from the sphere granular finish. Reasonable seed for Blender, Substance, Keyshot, Rhino — tune per material.

# finish:      granular
albedo        #c8bfa8
metallic      0.00
roughness     0.85
ior           1.45
transmission  0.00
clearcoat     0.00
sheen         0.00
anisotropic   0.00
copy as JSON 
{
  "albedo": "#c8bfa8",
  "metallic": 0.0,
  "roughness": 0.85,
  "ior": 1.45,
  "transmission": 0.0,
  "clearcoat": 0.0,
  "sheen": 0.0,
  "anisotropic": 0.0
}
Blender 4.x Python 
# Blender 4.x — Principled BSDF
# Limestone · finish: granular
import bpy
mat = bpy.data.materials.new(name="mat_limestone")
mat.use_nodes = True
bsdf = mat.node_tree.nodes["Principled BSDF"]
bsdf.inputs["Base Color"].default_value         = (0.5776, 0.521, 0.3916, 1.0)
bsdf.inputs["Metallic"].default_value           = 0.000
bsdf.inputs["Roughness"].default_value          = 0.850
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
# Limestone · finish: granular
# Run from Window → Scripting Console
import lux
mat = lux.createMaterial(name="mat_limestone", materialType="Generic")
mat.setProperty("diffuse",      (200, 191, 168))   # 8-bit sRGB
mat.setProperty("metallic",     0.000)
mat.setProperty("roughness",    0.850)
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": "Limestone \u00b7 finish: granular",
  "baseColor": {
    "r": 0.5776,
    "g": 0.521,
    "b": 0.3916
  },
  "metallic": 0.0,
  "roughness": 0.85,
  "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_limestone",
      "pbrMetallicRoughness": {
        "baseColorFactor": [
          0.5776,
          0.521,
          0.3916,
          1.0
        ],
        "metallicFactor": 0.0,
        "roughnessFactor": 0.85
      },
      "extensions": {
        "KHR_materials_ior": {
          "ior": 1.45
        }
      }
    }
  ]
}
USD Preview Surface 
# USD Preview Surface — UsdShade.MaterialLook prim attributes
# Limestone · finish: granular
def Material "mat_limestone" {
    token outputs:surface.connect = </mat_limestone/PreviewSurface.outputs:surface>

    def Shader "PreviewSurface" {
        uniform token info:id = "UsdPreviewSurface"
        color3f inputs:diffuseColor = (0.5776, 0.521, 0.3916)
        float   inputs:metallic     = 0.000
        float   inputs:roughness    = 0.850
        float   inputs:ior          = 1.450
        float   inputs:opacity      = 1.000
        float   inputs:clearcoat    = 0.000
        token   outputs:surface
    }
}
↓ download glTF material
ProcessStone Carving (Hand and Pneumatic) · Water-Jet Cutting
Used inArchitectural Facade Panel · Bronze Cast Sculpture
Substitutes
Granite
Portland Cement Concrete

Citations