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Rock Weight Calculator and Density Chart

A rock weight estimate is a mass calculation: mass equals volume multiplied by mass density. Strictly, weight is a force, but everyday searches use rock weight to mean mass, so GeoMiner reports kilograms, pounds, and metric tonnes. The SI density unit is kilograms per cubic metre; one gram per cubic centimetre equals 1,000 kilograms per cubic metre and approximately 62.428 pounds per cubic foot. The density chart uses five transparent, illustrative calculator presets: sandstone 2.30 grams per cubic centimetre, or 2,300 kilograms per cubic metre and 143.6 pounds per cubic foot; limestone 2.55, or 2,550 and 159.2; quartzite 2.65, or 2,650 and 165.4; granite 2.67, or 2,670 and 166.7; and basalt 2.90, or 2,900 and 181.0. These are single-point orientation values, not universal ranges, measured values, or design inputs. Choose a volume method first. A rectangular approximation multiplies length, width, and height. A sphere uses four-thirds pi times radius cubed, with radius equal to half the measured diameter. A cylinder uses pi times radius squared times length and is useful for regular drill core or cylindrical specimens. A measured volume can be entered directly in cubic centimetres, litres, cubic metres, cubic inches, or cubic feet. Keep units consistent and multiply by quantity only after calculating one object's volume. Geometry is often the largest uncertainty: an enclosing box includes empty corners, a sphere ignores irregular faces, and a cylinder ignores taper, broken ends, and voids. Water displacement can better represent a small irregular specimen only when the material is known to be stable and water-compatible. Trapped air and water entering connected pores still bias the result. Never immerse soluble, friable, porous, swelling, reactive, contaminated, valuable, mounted, fragile, or unknown material. Density is not one fixed number per rock name. Mineral proportions, pores, fractures, weathering, alteration, moisture, saturation, temperature, and measurement method all affect bulk density. Published granite, sandstone, limestone, basalt, and quartzite values are illustrative starting references, not certificates for an unknown rock. Specific gravity, particle density, dry bulk density, saturated bulk density, and in-place bulk density are related but not interchangeable. Record the property, moisture condition, specimen representativeness, and meth

  • Specific gravity calculator — Measure a compatible specimen by suspended weight or displacement instead of assuming a rock-type value.
  • Quick ID by properties — Build a non-destructive material shortlist from multiple observable properties.
  • Specimen label maker — Keep identity, source, condition, and measurement context attached to the specimen.
  • Identification test procedures — Review evidence limits and safer test methods before changing or immersing a specimen.
  • GeoMiner methodology — Understand evidence, uncertainty, privacy, source, and safety standards used across the platform.

Verification resources

Cross-check terminology, classification, methods, and safety with these authoritative external resources.

  • undefined. The formal definition of mass density as mass divided by volume and the SI unit kilogram per cubic metre.
  • undefined. Authoritative conversions among grams per cubic centimetre, kilograms per cubic metre, pounds per cubic foot, and related density units.
  • undefined. Cubic metre as the SI volume unit and the relationship between litres and cubic metres.
  • undefined. Published ranges and representative values showing that density varies within and between sedimentary, igneous, and metamorphic rock types.
  • undefined. Definitions and measurement context for bulk density, dry unit weight, particle density, porosity, and moisture-related differences.

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Common questions

How do I estimate the weight of a rock?
Estimate or measure its volume, multiply by an appropriate bulk density, and keep the units consistent. A scale is better whenever the rock can be weighed safely.
What density should I use for a rock?
Use a measured bulk density for the actual material when accuracy matters. For orientation, this tool lists illustrative values of 2.30 g/cm³ for sandstone, 2.55 for limestone, 2.65 for quartzite, 2.67 for granite, and 2.90 for basalt. Actual rock varies with mineralogy, pores, fractures, weathering, and water content.
How do I estimate the volume of an irregular rock?
For a safe, stable, water-compatible specimen, measured displacement may be more representative than a simple shape. Never immerse soluble, porous, reactive, fragile, contaminated, valuable, mounted, or unknown material.
Is mass the same as weight?
Strictly, mass is measured in kilograms and weight is a force. Everyday searches use rock weight to mean mass, so the calculator reports kilograms, pounds, and metric tonnes.
Can I use this estimate for lifting, transport, or engineering design?
No. Shape and assumed density can create large errors. Use verified measurements, project-grade density data, applicable factors, and qualified planning for consequential work.

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