Density Calculator: Measure Object Density with Precision
Calculate the density of any object instantly using mass and volume. Perfect for students, engineers, and scientists who need accurate density measurements.
grams (g)
cubic centimeters (cm³)
Module A: Introduction & Importance of Density Calculations
Understanding how to calculate the density of an object is fundamental across physics, chemistry, engineering, and materials science. This comprehensive guide explains why density matters and how to measure it accurately.
Density (represented by the Greek letter ρ “rho”) is a fundamental physical property that quantifies how much mass is contained within a given volume. The standard formula for density calculation is:
Density (ρ) = Mass (m) / Volume (V)
Where:
- ρ (rho) = Density (typically measured in g/cm³ or kg/m³)
- m = Mass of the object (grams or kilograms)
- V = Volume of the object (cubic centimeters or cubic meters)
Why Density Calculations Matter
Density calculations have profound implications across multiple disciplines:
- Material Identification: Density is a unique “fingerprint” for pure substances. For example, gold has a density of 19.32 g/cm³, while pyrite (“fool’s gold”) has a density of only 5.01 g/cm³.
- Engineering Applications: Aerospace engineers calculate density to determine optimal materials for aircraft components where weight reduction is critical.
- Environmental Science: Oceanographers measure seawater density to study currents and climate patterns.
- Medical Diagnostics: Bone density measurements help diagnose osteoporosis and other medical conditions.
- Manufacturing Quality Control: Consistent density ensures product uniformity in industries from pharmaceuticals to construction materials.
According to the National Institute of Standards and Technology (NIST), precise density measurements are essential for maintaining international measurement standards and ensuring global trade fairness.
Module B: How to Use This Density Calculator
Follow these step-by-step instructions to get accurate density calculations for any object using our interactive tool.
Step 1: Gather Your Measurements
Before using the calculator, you’ll need two key pieces of information:
- Mass: Weigh your object using a precision scale. For best results:
- Use a digital scale with at least 0.01g precision
- Tare the scale (reset to zero) before placing your object
- Record the mass in grams for this calculator
- Volume: Determine your object’s volume using one of these methods:
- Regular shapes: Use geometric formulas (V = l × w × h for rectangles)
- Irregular shapes: Use the water displacement method
- Liquids: Use a graduated cylinder
Step 2: Enter Your Values
- In the “Mass” field, enter your object’s weight in grams
- In the “Volume” field, enter your object’s volume in cubic centimeters (cm³)
- (Optional) Select your object’s material from the dropdown for comparison
Step 3: Calculate and Interpret Results
After clicking “Calculate Density”, you’ll see three key pieces of information:
- Calculated Density: Your object’s precise density in g/cm³
- Material Comparison: How your result compares to known materials
- Classification: Whether your object would float/sink in water (density >1.0 g/cm³ sinks)
Step 4: Analyze the Visualization
The interactive chart shows:
- Your calculated density (blue bar)
- Reference densities for common materials (gray bars)
- Water density baseline at 1.0 g/cm³ (red line)
Pro Tip: For irregular objects, use the water displacement method:
- Fill a graduated cylinder with water and record the initial volume
- Gently submerge your object and record the new volume
- Subtract the initial volume from the new volume to get your object’s volume
Module C: Formula & Methodology Behind Density Calculations
Understand the scientific principles and mathematical foundations that power our density calculator tool.
The Fundamental Density Equation
The density calculation is governed by this core equation:
ρ = m/V
ρ (rho)
Density
(g/cm³ or kg/m³)
(g/cm³ or kg/m³)
m
Mass
(grams or kilograms)
(grams or kilograms)
V
Volume
(cm³ or m³)
(cm³ or m³)
Unit Conversions and Dimensional Analysis
Our calculator uses grams and cubic centimeters, but density can be expressed in various units:
| Mass Unit | Volume Unit | Resulting Density Unit | Conversion Factor to g/cm³ |
|---|---|---|---|
| grams (g) | cubic centimeters (cm³) | g/cm³ | 1 |
| kilograms (kg) | cubic meters (m³) | kg/m³ | 0.001 |
| pounds (lb) | cubic inches (in³) | lb/in³ | 27.68 |
| ounces (oz) | cubic inches (in³) | oz/in³ | 1.73 |
| grams (g) | milliliters (mL) | g/mL | 1 (since 1 mL = 1 cm³) |
Scientific Principles Behind the Calculation
The density calculation relies on several fundamental scientific concepts:
- Conservation of Mass: An object’s mass remains constant regardless of its location (on Earth or in space).
- Additivity of Volumes: For composite objects, total volume is the sum of individual component volumes.
- Archimedes’ Principle: The buoyant force on a submerged object equals the weight of the fluid it displaces.
- Temperature Dependence: Most materials expand when heated, decreasing their density (except water between 0-4°C).
For advanced applications, the NIST Physical Measurement Laboratory provides comprehensive data on material properties and measurement techniques.
Calculation Limitations and Considerations
- Porous Materials: Objects with internal voids (like sponges) require special handling to measure only the solid portion’s volume.
- Temperature Effects: Density values in reference tables are typically given at 20°C. Significant temperature variations may require adjustments.
- Pressure Effects: For gases and some liquids, pressure significantly affects density (ideal gas law: PV = nRT).
- Measurement Precision: Your result’s accuracy cannot exceed the precision of your least precise measurement.
Module D: Real-World Density Calculation Examples
Explore these detailed case studies demonstrating practical density calculations across different scenarios.
Case Study 1: Gold Ring Authentication
Scenario: A jeweler needs to verify if a ring is made of pure gold (24K) as claimed by the seller.
Given:
- Mass = 10.5 grams (measured on precision scale)
- Volume = 0.543 cm³ (measured via water displacement)
Calculation:
ρ = mass/volume = 10.5g / 0.543cm³ = 19.34 g/cm³
Analysis: The calculated density (19.34 g/cm³) matches the known density of pure gold (19.32 g/cm³), confirming the ring’s authenticity within measurement tolerance.
Case Study 2: Aircraft Component Material Selection
Scenario: An aerospace engineer compares aluminum and titanium for a new aircraft component that must weigh ≤500g with volume constraints of 250 cm³.
| Material | Density (g/cm³) | Component Mass | Weight Savings vs. Titanium |
|---|---|---|---|
| Aluminum (7075) | 2.80 | 700g (250 × 2.80) | +200g (overweight) |
| Titanium (Grade 5) | 4.43 | 1107.5g (250 × 4.43) | 0g (baseline) |
| Aluminum-Lithium Alloy | 2.55 | 637.5g (250 × 2.55) | -132.5g (acceptable) |
Decision: The engineer selects the aluminum-lithium alloy, achieving the required weight while maintaining structural integrity. The density calculation revealed that standard aluminum would exceed weight limits, while titanium would be unnecessarily heavy.
Case Study 3: Environmental Water Quality Testing
Scenario: An environmental scientist tests water samples from a lake to detect potential pollution.
Given:
- Sample 1 (surface): Mass = 102.5g, Volume = 100 mL
- Sample 2 (deep): Mass = 103.2g, Volume = 100 mL
- Pure water reference: 1.00 g/cm³ at 20°C
Calculations:
Sample 1: ρ = 102.5g / 100cm³ = 1.025 g/cm³
Sample 2: ρ = 103.2g / 100cm³ = 1.032 g/cm³
Analysis: Both samples show elevated density (1.025-1.032 g/cm³ vs. 1.00 g/cm³ for pure water), suggesting dissolved solids or pollutants. The deeper sample’s higher density indicates potential stratification of contaminants. According to EPA guidelines, this warrants further chemical analysis.
Module E: Density Data & Comparative Statistics
Explore comprehensive density data for various materials and understand how they compare in real-world applications.
Table 1: Density Comparison of Common Elements and Compounds
| Material | Density (g/cm³) | Classification | Key Properties | Common Uses |
|---|---|---|---|---|
| Osmium | 22.59 | Metal | Hardest pure metal, high corrosion resistance | Electrical contacts, fountain pen tips |
| Iridium | 22.56 | Metal | Extreme corrosion resistance, high melting point | Spark plugs, crucibles for high-temperature applications |
| Platinum | 21.45 | Metal | Ductile, corrosion-resistant, excellent catalyst | Catalytic converters, jewelry, laboratory equipment |
| Gold | 19.32 | Metal | Malleable, excellent conductor, corrosion-resistant | Jewelry, electronics, monetary reserves |
| Tungsten | 19.25 | Metal | Highest melting point of all metals, extremely strong | Filaments, armor-piercing ammunition, electrical contacts |
| Uranium | 19.05 | Metal | Radioactive, dense, weakly radioactive in natural form | Nuclear fuel, radiation shielding, counterweights |
| Mercury | 13.53 | Liquid Metal | Only metal liquid at room temperature, excellent conductor | Thermometers, barometers, fluorescent lamps |
| Lead | 11.34 | Metal | Soft, malleable, high corrosion resistance | Batteries, radiation shielding, ammunition |
| Silver | 10.49 | Metal | Best electrical/thermal conductor, lustrous | Jewelry, electronics, photography, mirrors |
| Copper | 8.96 | Metal | Excellent conductor, malleable, corrosion-resistant | Electrical wiring, plumbing, cookware |
| Iron | 7.87 | Metal | Ferromagnetic, abundant, strong | Steel production, tools, structural components |
| Aluminum | 2.70 | Metal | Lightweight, corrosion-resistant, good conductor | Aircraft parts, beverage cans, construction |
| Magnesium | 1.74 | Metal | Lightest structural metal, flammable in powder form | Aircraft components, fireworks, medical implants |
| Water (4°C) | 1.00 | Liquid | Universal solvent, maximum density at 4°C | Essential for life, industrial processes, cooling |
| Ice | 0.92 | Solid | Less dense than liquid water, floats | Cooling, preservation, recreational |
| Wood (Oak) | 0.75 | Organic | Porous, anisotropic, renewable | Furniture, construction, flooring |
| Wood (Balsa) | 0.16 | Organic | Extremely lightweight, buoyant | Model building, insulation, lightweight structures |
| Air (1 atm, 20°C) | 0.0012 | Gas | Compressible, variable composition | Breathing, combustion, pneumatic systems |
Table 2: Density Variations with Temperature for Common Substances
Density typically decreases as temperature increases due to thermal expansion (except water between 0-4°C).
| Substance | 0°C | 20°C | 50°C | 100°C | Notes |
|---|---|---|---|---|---|
| Water | 0.9998 | 0.9982 | 0.9881 | 0.9584 | Maximum density at 3.98°C (1.0000 g/cm³) |
| Ethanol | 0.8063 | 0.7893 | 0.7721 | 0.7566 | Volatile, flammable, used in beverages and fuel |
| Mercury | 13.595 | 13.534 | 13.452 | 13.350 | Only metal liquid at room temperature |
| Aluminum | 2.712 | 2.700 | 2.681 | 2.654 | Lightweight metal with high thermal expansion |
| Copper | 8.960 | 8.933 | 8.889 | 8.826 | Excellent electrical conductor |
| Air (1 atm) | 0.001293 | 0.001205 | 0.001093 | 0.000946 | Density highly pressure-dependent |
| Olive Oil | 0.921 | 0.915 | 0.905 | 0.890 | Less dense than water, floats |
Key Insight: The density differences between similar materials (like aluminum alloys) can determine their suitability for specific applications. For example, the 7075 aluminum alloy (2.80 g/cm³) is 9% denser than 6061 alloy (2.70 g/cm³), which significantly impacts weight-critical aerospace components.
Module F: Expert Tips for Accurate Density Measurements
Master these professional techniques to ensure precise density calculations in laboratory and field settings.
Measurement Techniques for Different Object Types
- Regular Solids (cubes, spheres, cylinders):
- Use calipers or rulers to measure dimensions
- Apply appropriate geometric formulas:
- Cube: V = side³
- Sphere: V = (4/3)πr³
- Cylinder: V = πr²h
- For highest precision, measure each dimension 3 times and average
- Irregular Solids:
- Use the water displacement method (Archimedes’ principle)
- For porous materials, coat with a thin waterproof film (like paraffin) first
- Use a meniscus reader for precise volume measurements
- Liquids:
- Use a pycnometer or density bottle for highest accuracy
- Account for temperature – most liquid densities are given at 20°C
- For viscous liquids, allow time for air bubbles to rise
- Gases:
- Use the ideal gas law: PV = nRT
- Measure pressure with a manometer and temperature with a thermocouple
- For gas mixtures, calculate partial densities of each component
Advanced Techniques for Challenging Materials
- Porous Materials:
- Use helium pycnometry to measure true volume excluding pores
- For open-cell foams, use both geometric and displacement methods
- Calculate “apparent density” (mass/geometric volume) and “true density” (mass/true volume)
- Powders and Granular Materials:
- Use a tap density tester to measure both loose and tapped densities
- Calculate Hausner ratio (tapped density/loose density) to assess flow properties
- For pharmaceuticals, follow USP <616> bulk density guidelines
- Composite Materials:
- Calculate theoretical density using rule of mixtures
- Compare with measured density to assess porosity
- Use ultrasound or X-ray tomography for internal structure analysis
Common Pitfalls and How to Avoid Them
| Potential Error | Cause | Prevention Method |
|---|---|---|
| Air bubbles in liquid displacement | Improper submergence technique | Use a fine wire to hold object below surface; tap container to release bubbles |
| Temperature variations | Uncontrolled lab environment | Use temperature-controlled water bath; record all temperatures |
| Absorption of water by object | Porous or hygroscopic materials | Coat with waterproof film; use quick measurements; dry thoroughly beforehand |
| Parallax error in readings | Improper viewing angle of meniscus | Read at eye level; use meniscus finder; average multiple readings |
| Scale calibration issues | Improperly calibrated balance | Calibrate with standard weights daily; use NIST-traceable weights |
| Volume measurement errors | Incorrect graduated cylinder use | Use smallest appropriate cylinder; read at bottom of meniscus |
| Material non-uniformity | Inhomogeneous samples | Take multiple samples; use statistical analysis; consider material history |
Equipment Recommendations for Different Precision Levels
| Precision Level | Mass Measurement | Volume Measurement | Typical Applications |
|---|---|---|---|
| Basic (±1%) | Digital kitchen scale (±1g) | Graduated cylinder (±5 mL) | Educational demonstrations, rough estimates |
| Standard (±0.1%) | Top-loading balance (±0.01g) | Burette or pipette (±0.1 mL) | High school/college labs, quality control |
| High (±0.01%) | Analytical balance (±0.0001g) | Volumetric flask (±0.05 mL) | Research labs, pharmaceutical development |
| Ultra-high (±0.001%) | Microbalance (±0.00001g) in controlled environment | Pycnometer with temperature control (±0.001 mL) | Metrology labs, standards development, advanced materials research |
Module G: Interactive Density Calculator FAQ
Find answers to the most common questions about density calculations and our interactive tool.
How accurate is this density calculator compared to laboratory methods?
Our calculator provides theoretical accuracy limited only by the precision of your input values. The calculation itself uses the fundamental density formula (ρ = m/V) with full floating-point precision (up to 15 decimal places in JavaScript).
Comparison with lab methods:
- Water displacement: ±0.5-2% (depending on technique)
- Pycnometer: ±0.1-0.5%
- Digital density meter: ±0.001-0.01%
- Our calculator: Limited by your measurement precision
For critical applications, we recommend:
- Using calibrated equipment (NIST-traceable weights)
- Taking multiple measurements and averaging
- Controlling temperature (most reference densities are at 20°C)
- Accounting for air buoyancy in precise measurements
Why does my calculated density not match the expected value for known materials?
Discrepancies between your calculated density and reference values typically result from:
- Measurement Errors:
- Mass: Scale not properly calibrated or tared
- Volume: Incorrect water displacement technique or meniscus reading
- Material Factors:
- Alloys or impurities (e.g., 18K gold is only 75% gold)
- Porosity or internal voids (common in castings)
- Surface coatings or oxidation layers
- Environmental Factors:
- Temperature differences (most reference densities are at 20°C)
- Air pressure variations (affects gas densities)
- Humidity absorption (especially for hygroscopic materials)
- Calculation Issues:
- Unit mismatches (ensure mass is in grams and volume in cm³)
- Rounding errors in intermediate steps
- Incorrect formula application for composite materials
Troubleshooting steps:
- Verify all measurements with a second method
- Check for air bubbles during water displacement
- Ensure the object is completely submerged
- Compare with multiple reference sources
- Consider material certification or composition analysis
Can this calculator be used for gases or only solids and liquids?
While our calculator can technically process any mass and volume inputs, special considerations apply for gases:
Key Differences for Gas Density Calculations:
| Factor | Solids/Liquids | Gases |
|---|---|---|
| Density Range | 0.1 – 20+ g/cm³ | 0.0001 – 0.01 g/cm³ |
| Primary Dependence | Material composition | Temperature & pressure |
| Measurement Method | Direct mass/volume | Ideal gas law (PV=nRT) |
| Compressibility | Negligible | Significant |
For accurate gas density calculations:
- Use the ideal gas law: ρ = PM/RT where:
- P = pressure (atm)
- M = molar mass (g/mol)
- R = ideal gas constant (0.0821 L·atm/mol·K)
- T = temperature (Kelvin)
- Measure temperature in Kelvin (K = °C + 273.15)
- Account for water vapor pressure in air measurements
- For gas mixtures, calculate partial densities of each component
Example: Air density at 1 atm and 20°C = (1 × 28.97) / (0.0821 × 293.15) = 1.204 g/L = 0.001204 g/cm³
How does temperature affect density calculations and when should I adjust for it?
Temperature significantly impacts density through thermal expansion. Most materials expand when heated, decreasing their density (water between 0-4°C is a notable exception).
Temperature Adjustment Guidelines:
| Material Type | Typical Coefficient | When to Adjust | Adjustment Method |
|---|---|---|---|
| Metals | ~0.00003/°C | ΔT > 20°C from reference | ρ = ρ₀ / [1 + β(T – T₀)] |
| Liquids | ~0.0005/°C | ΔT > 5°C from reference | Use published temperature-density tables |
| Gases | ~0.0034/°C (ideal) | Always | Use ideal gas law with actual temperature |
| Water | Non-linear | Always | Use standard water density tables |
Practical Temperature Adjustment Steps:
- Determine your measurement temperature (T)
- Find the reference temperature (T₀) for published density values (usually 20°C)
- Calculate temperature difference (ΔT = T – T₀)
- Apply correction:
- For solids: ρ = ρ₀ / [1 + β(ΔT)]
- β = volumetric thermal expansion coefficient
- Example for aluminum: β = 0.00007/°C
- For liquids: Use published temperature-density curves
- For gases: Recalculate using actual temperature in ideal gas law
- For solids: ρ = ρ₀ / [1 + β(ΔT)]
Critical Note: Water reaches maximum density at 3.98°C (1.0000 g/cm³). Between 0-4°C, water contracts when heated, making density increase with temperature in this range.
What are the most common real-world applications of density calculations?
Density calculations have diverse applications across industries and scientific disciplines:
Industrial and Engineering Applications:
- Aerospace:
- Material selection for aircraft components (aluminum vs. titanium tradeoffs)
- Fuel density calculations for weight and balance
- Composite material development (fiber-reinforced polymers)
- Automotive:
- Battery design (lithium-ion vs. lead-acid energy density)
- Crash structure optimization (energy absorption vs. weight)
- Fuel efficiency calculations
- Construction:
- Concrete mix design (density affects strength and durability)
- Insulation material selection (low-density materials for thermal resistance)
- Soil compaction testing (density indicates load-bearing capacity)
- Manufacturing:
- Quality control for porous materials (ceramic filters, catalysts)
- Powder metallurgy (pressing and sintering density control)
- Packaging optimization (maximizing product density for shipping)
Scientific and Medical Applications:
- Material Science:
- Developing new alloys with specific density requirements
- Characterizing nanomaterials and aerogels
- Studying phase transitions (solid-liquid-gas density changes)
- Geology:
- Mineral identification (density is a key diagnostic property)
- Ore grade estimation (density correlates with metal content)
- Volcanic rock analysis (vesicularity affects density)
- Medicine:
- Bone density measurements (osteoporosis diagnosis)
- Contrast agent development for imaging
- Pharmaceutical tablet formulation (density affects dissolution rates)
- Environmental Science:
- Water quality monitoring (density indicates pollution)
- Ocean current modeling (density drives thermohaline circulation)
- Atmospheric studies (air density affects weather patterns)
Everyday Applications:
- Cooking:
- Adjusting recipes for high-altitude baking (lower air density)
- Determining fat content in milk (density varies with cream content)
- Calibrating kitchen scales using water density
- Sports:
- Golf ball design (density distribution affects flight)
- Swimwear material selection (buoyancy optimization)
- Scuba diving weight calculations
- Home Improvement:
- Choosing insulation materials (R-value relates to density)
- Selecting flooring materials (density affects durability and sound transmission)
- Determining paint coverage (density affects spreading rate)
How can I calculate the density of an object that floats in water?
Floating objects present a special challenge because you can’t fully submerge them using standard water displacement methods. Here are three effective techniques:
Method 1: Two-Liquid Displacement (Recommended)
- Choose a liquid denser than your object (e.g., ethanol for objects that float in water but sink in ethanol)
- Measure mass of object (m) using a scale
- Fill graduated cylinder with the dense liquid and record initial volume (V₁)
- Gently submerge the object and record new volume (V₂)
- Calculate volume: V = V₂ – V₁
- Calculate density: ρ = m/V
Common dense liquids:
| Liquid | Density (g/cm³) | Safety Notes |
|---|---|---|
| Ethanol (100%) | 0.789 | Flammable, use in well-ventilated area |
| Isopropyl Alcohol | 0.786 | Flammable, irritant |
| Olive Oil | 0.92 | Non-toxic, may stain |
| Glycerin | 1.26 | Non-toxic, viscous |
| Saturated Salt Water | ~1.20 | Non-toxic, may corrode metals |
Method 2: Weighted Submersion
- Attach a dense weight (like a metal washer) to the floating object
- Ensure the combined object sinks
- Measure mass of object + weight (m₁)
- Measure mass of weight alone (m₂)
- Submerge the combined object and measure displaced volume (V)
- Calculate object mass: m = m₁ – m₂
- Calculate density: ρ = m/V
Method 3: Buoyant Force Calculation
- Measure mass of object in air (m)
- Measure apparent mass when floating (mₐ) by supporting it on a scale with a thin wire
- Calculate buoyant force: F_b = m – mₐ
- Calculate displaced water volume: V = F_b / (ρ_water × g)
- Calculate density: ρ = m/V
Pro Tip: For very buoyant objects (like cork or Styrofoam), use a combination of weighted submersion and the two-liquid method for best accuracy. Always account for the density of any attached weights in your calculations.
Can this calculator help determine if an object is hollow or contains hidden compartments?
Yes! Density calculations are an excellent non-destructive method to detect hidden cavities or internal structures. Here’s how to analyze your results:
Hollow Object Detection Method:
- Calculate Expected Density:
- Determine the material composition (e.g., “supposed to be solid gold”)
- Look up the reference density for that material
- Measure Actual Density:
- Use our calculator with your object’s mass and volume
- For irregular objects, use water displacement for volume
- Compare Values:
- If actual density is significantly lower than expected, the object likely contains voids
- Calculate the percentage difference: [(expected – actual)/expected] × 100%
- Estimate Void Volume:
- Calculate expected mass if solid: m_expected = ρ_reference × V_measured
- Difference = m_expected – m_actual
- Void volume = (m_expected – m_actual) / ρ_reference
Interpretation Guide:
| Density Difference | Likely Explanation | Example |
|---|---|---|
| < 2% | Measurement error or minor impurities | High-purity gold jewelry |
| 2-10% | Alloying or significant impurities | 14K gold (58.3% gold) |
| 10-30% | Substantial hollow sections or low-density core | Gold-plated tungsten “fake gold bars” |
| 30-70% | Mostly hollow with thin walls | Decorative hollow metal sculptures |
| > 70% | Extremely lightweight core or composite structure | Modern aerospace honeycomb panels |
Case Study: Detecting Counterfeit Gold Bars
A standard gold bar (99.99% pure) should have:
- Mass: 12.44 kg (for a 400 oz bar)
- Volume: 643.8 cm³ (12.44 kg / 19.32 g/cm³)
- Dimensions: ~21.0 × 11.0 × 5.5 cm
Common counterfeit methods and their density signatures:
- Tungsten Core:
- Tungsten has similar density to gold (19.25 vs 19.32 g/cm³)
- Detection requires drilling or X-ray fluorescence
- Density test alone may not detect (difference < 0.4%)
- Lead Core:
- Lead density = 11.34 g/cm³
- Resulting bar density ~15-16 g/cm³
- Easy to detect (20-25% density difference)
- Hollow Core:
- Air density = 0.0012 g/cm³
- Resulting bar density ~10-15 g/cm³
- Very easy to detect (25-50% density difference)
- Partial Gold Plating:
- Base metal (e.g., copper) with gold plating
- Resulting density ~12-14 g/cm³
- Detectable (25-40% density difference)
Important Note: For valuable items, density testing should be combined with other methods like:
- X-ray fluorescence (XRF) for elemental analysis
- Ultrasonic testing for internal structure
- Magnetic testing (gold is non-magnetic)
- Acid testing (for gold specifically)