Gold is a unique and highly valued metal renowned for its distinct properties and historical significance. One of the most critical physical properties of gold is its mass density, which provides insights into its heaviness and contributes to its various applications, from jewelry to electronics.
Definition and Units
Mass density, also known simply as density, is defined as the mass of an object per unit volume. It is commonly expressed in units of grams per cubic centimeter (g/cm³) or kilograms per cubic meter (kg/m³). For gold, this property is crucial in determining its weight and, consequently, its value and usability in different applications.
Fundamental Properties of Gold
Gold (Au) is a transition metal with an atomic number of 79 and an atomic mass of approximately 197 atomic mass units (amu). It is characterized by its distinctive yellow hue, high luster, and excellent resistance to corrosion and tarnish. The metal’s density is a critical parameter that plays a significant role in its practical applications and value.
What is the Density of Gold?
The mass density of pure gold is approximately 19.3 g/cm³ This high density reflects gold’s status as one of the densest naturally occurring metals. This value can vary slightly depending on the purity of the gold and the presence of alloying elements. Pure gold, also known as 24-carat gold, maintains this density value consistently.
Density of Gold kg/m3
The density of gold is approximately 19,300 kg/m³.
Density of Gold Ib/in3
The density of gold is approximately 0.7 lb/in³.
Density Variations in Gold Alloys
Gold is often alloyed with other metals to improve its hardness or alter its color. These alloys include silver, copper, and nickel, among others. The density of these gold alloys varies depending on the proportion and type of the alloying metal:
- 18-Carat Gold (75% Gold): The density of 18-carat gold is typically around 15.6 g/cm³. This reduction from pure gold’s density is due to the lower gold content and the inclusion of other metals.
- 14-Carat Gold (58.3% Gold): This alloy has a density of approximately 12.9 g/cm³. The decrease in density compared to pure gold results from the higher proportion of base metals mixed with gold.
- 10-Carat Gold (41.7% Gold): With even less gold content, 10-carat gold has a density of around 10.0 g/cm³. This lower density reflects the substantial presence of non-gold metals in the alloy.
Comparison with Other Metals
To put this in perspective, gold is denser than many other metals. For instance, lead, which has a density of around 11.35 g/cm³ (Learn more about lead density), is significantly lighter than gold. Even osmium and iridium, which are among the densest naturally occurring elements, have densities of about 22.59 g/cm³ and 22.56 g/cm³, respectively, making gold slightly less dense but still exceptionally heavy.
To provide a broader perspective, here are some additional comparisons:
| Metal | Density (g/cm³) | Density (kg/m³) | Density (lb/in³) |
|---|---|---|---|
| Platinum | 19.9 | 19,900 | 0.7 |
| Iridium | 22.6 | 22,600 | 0.8 |
| Rhenium | 21.0 | 21,000 | 0.8 |
| Osmium | 22.6 | 22,600 | 0.8 |
| Silver | 10.5 | 10,500 | 0.4 |
| Nickel | 8.9 | 8,900 | 0.3 |
| Copper | 9.0 | 9,000 | 0.3 |
| Titanium | 4.5 | 4,500 | 0.2 |
| Aluminum | 2.7 | 2,700 | 0.1 |
| Zinc | 7.1 | 7,100 | 0.3 |
| Iron | 7.9 | 7,900 | 0.3 |
| Chromium | 7.2 | 7,200 | 0.3 |
| Cobalt | 8.9 | 8,900 | 0.3 |
Factors Affecting the Density of Gold
Several factors can influence the density of gold:
Atomic Structure
Gold’s density is influenced by its atomic mass and the packing efficiency of its atoms in the crystal lattice. Gold has a face-centered cubic (FCC) crystal structure, which contributes to its high density. In this structure, atoms are closely packed, minimizing the amount of empty space and leading to a high mass per unit volume.
Purity
The density of gold can vary slightly depending on its purity. Pure gold, with a density of 19.32 g/cm³, is the standard reference. However, gold alloys, which contain other metals such as copper or silver, can have different densities. For example, an alloy like 18-karat gold, which contains 75% gold, will have a slightly lower density than pure gold.
Applications and Implications of Gold’s Density
- Jewelry: The high density of gold contributes to its luxurious feel and substantial weight in jewelry. The density helps jewelers and consumers differentiate between pure gold and gold-plated or gold-filled items.
- Electronics: Gold’s density and excellent conductivity make it valuable in electronic components. Its high density ensures that gold contacts and connectors are reliable and durable.
- Finance and Investment: Gold’s density, along with its high value, plays a role in its use as a standard for measuring wealth and a hedge against economic instability. The density impacts the size and weight of gold bullion, bars, and coins.
- Aerospace: In aerospace applications, gold’s density impacts its use in various components, where both its weight and its resistance to corrosion are important. The high density ensures that components are durable while maintaining a manageable volume.
Density of Gold vs Tungsten
Gold and tungsten have very similar densities, with gold at approximately 19.3 g/cm³ and tungsten slightly less at around 19.2 g/cm³. This minor difference means that, for the same volume, gold is a bit heavier. Gold’s higher density contributes to its value in jewelry and electronics, while tungsten’s density, combined with its hardness and high melting point, makes it ideal for heavy-duty industrial applications.
The following is a detailed comparison table of differences:
| Property | Gold | Tungsten |
|---|---|---|
| Density | 19.3 g/cm³ | 19.2 g/cm³ |
| Atomic Structure | Face-Centered Cubic (FCC) | Body-Centered Cubic (BCC) |
| Primary Uses | Jewelry, investment, electronics | Cutting tools, lightbulb filaments, high-density alloys |
| Melting Point | 1064°C | 3422°C |
| Hardness | Moderate (malleable) | High (very hard) |
| Malleability | High (easily workable) | Low (difficult to work) |
Why is Gold So Dense?
Gold’s high density is primarily due to its atomic structure and atomic mass. The density of a material is influenced by both the mass of its atoms and how closely they are packed together in the solid form.
- Atomic Mass: Gold atoms are relatively heavy compared to many other elements. Each gold atom has a high atomic mass, contributing significantly to the overall density of the material.
- Atomic Structure: Gold has a face-centered cubic (FCC) crystal structure, where atoms are packed closely together. This efficient packing means that a large number of atoms are packed into a small volume, further increasing its density.
- Heavy Nucleus: The nucleus of a gold atom contains a large number of protons and neutrons, which adds to the mass of the atom. This high atomic mass, combined with the compact atomic arrangement, results in gold’s high density.
How to Calculate Density of Gold?
To calculate gold’s density, divide its mass by its volume. Measure the mass in grams or kilograms and the volume in cubic centimeters or cubic meters. For example, if you have 1000 grams of gold with a volume of 51.8 cubic centimeters, the density is 1000 grams divided by 51.8 cm³, which is about 19.3 g/cm³.
Conclusion
Gold’s mass density of approximately 19.3 g/cm³ is a fundamental property that influences its applications and value. While the density of pure gold is well-established, variations in gold alloys highlight how alloying affects this property. Understanding these density values is essential for professionals across various industries, ensuring accurate assessments and optimal use of gold in their respective fields.
More Resources:
does gold rust – Source: BOYI
gold melting point – Source: BOYI
is gold magnetic – Source: BOYI
gold – Source: Wikipedia
FAQ
The density of 24-karat gold is approximately 19.3 grams per cubic centimeter (g/cm³). This high density is due to the metal’s pure form and closely packed atomic structure.
Gold is not the densest metal. While it is among the densest, the title of densest metal belongs to osmium and iridium, both of which have densities around 22.59 and 22.56 grams per cubic centimeter (g/cm³) respectively.
To find the weight of 1 cubic meter (m³) of gold, you can use its density. Given that gold has a density of approximately 19,300 kilograms per cubic meter (kg/m³), 1 m³ of gold would weigh 19,300 kg.
Catalog: Materials Guide
This article was written by engineers from the BOYI team. Fuquan Chen is a professional engineer and technical expert with 20 years of experience in rapid prototyping, mold manufacturing, and plastic injection molding.
