Diamond melting

What Is the Melting Point of Diamond?

If you’ve ever wondered, “What is the melting point of a diamond?” is the answer. You are not alone in your feelings. Many other materials, including diamonds, are tough to melt, making them laborious. Carbon atoms are securely linked together to form a strong structure in diamonds. Diamonds are more rigid than toothpicks, which are more prone to breaking. In turn, this increases their difficulty in melting and, as a result, their value. Despite this, the melting points of diamonds are still relatively high.

Carbon exists in the form of a diamond. A carbon bond links its carbon atoms to four other carbon atoms. It’s exceedingly difficult as a result of this. It is so complex that graphite, which has a melting point similar to that of diamond, melts at only three thousand degrees Celsius. This is due to the solid covalent connections formed by the diamond with the carbon atoms. Another critical distinction between diamond and graphite is that graphite does not melt under normal pressures. Diamond does, however.


What is the Melting Point of Diamond?

The ultimate melting point of the diamond is around 4,027° Celsius (7,280° Fahrenheit), which is the same as four thousand and twenty-seven degrees Celsius (or four thousand and twenty-seven degrees Celsius). However, this figure should only be used as a guideline and not be considered final. The exact melting point of a diamond is determined by the quality and size of the diamond. Therefore, smaller diamonds will melt at a lower temperature than larger ones due to this. While using heat on a diamond should be done with caution, it is worth trying if you are interested in learning more about diamonds.


The possibility of considerable quantities of pure Carbon residing in giant planets like Uranus and Neptune has acquired both scientific and theoretical backing since Ross postulated that there might be “diamonds in the sky” in 1981. Carbon’s high-pressure, high-temperature behavior is now widely acknowledged as critical for predicting the evolution and structure of such planets. Despite this, the melting temperature of diamond, which is one of the most critical thermal parameters, has never been directly measured. This is likely understandable because diamond is thermodynamically unstable, changing to graphite before melting at ambient pressure, and firmly bound, being the most challenging bulk material known. Shock-compression experiments on diamonds revealed the melting temperature of Carbon at pressures of 0.6–1.1 TPA (6–11 Mbar). According to the findings, they suggested that crystalline diamonds can be stable deep inside giant planets like Uranus and Neptune. The measurements demonstrate that diamond melts to a denser, metallic fluid between 0.60 and 1.05 TPA, with a negative Clapeyron slope on the melting curve, consistent with first-principles simulations’ predictions. Temperature data at even higher pressures indicate that diamond melts to a complicated fluid state.


There are many theoretical calculations of the high-pressure melting curve of diamond, with some predicting a maximum temperature at 500 GPa, due to the importance of high-pressure Carbon in both planetary science and inertial confinement fusion (for which high-density Carbon is a candidate ablator material for ignition target designs). Because direct temperature measurements in both static and dynamic high-pressure studies are difficult, melt-curve predictions have only been confirmed by inference rather than a direct measurement. Under static conditions, equations of state relevant to diamond melting do not extend much beyond 50 GPa. They imply a positive Clapeyron slope, (T/ P)melt>0, for diamonds up to 60 GPa. Dynamic shock investigations on graphite, which is supposed to transform to diamond under dynamic loading, indicate that the melting slope is positive up to 140 GPa. Finally, recent diamond shock studies have revealed a rise in density near 600 GPa, implying that shocked diamond could melt with a negative melt curve near 600 GPa.

The first temperature data for a shock-compressed diamond at 0.6–4 TPA (6–40 Mbar) and 8,000–100,000 K. The melting curve for Carbon up to 1.1 TPa is revealed, and a complex fluid state between 1.2 and 2.5 TPa. Shock studies typically investigate a steady-state Hugoniot with the shock velocity Us, particle velocity Up, pressure P, specific volume V, (=1/density), and internal energy E of the shocked material. The three Rankine–Hugoniot relations link these five variables, allowing the condition of the sample under shock loading to be determined by a single measurement if the P–V–E Hugoniot has been determined before. Our tests use an unsupported shock whose pressure decays over time while P, V, E, Us, and Up obey mass, momentum, and energy conservation at the shock front, resulting in the Rankine–Hugoniot relations. As the unsupported shock progresses through time and space, it samples a continuum of Hugoniot states. In the current studies, we measure the shock velocity Us and utilize the Sesame Hugoniot, which accurately depicts the compilation of new Hugoniot trials. We also assess our sample’s non-Rankine–Hugoniot variables T and reflectivity, R=532, at visible wavelengths (=532 nm).

We used the University of Rochester’s OMEGA laser to create diamond-target shocks by focusing one ns pulses of 351 nm light with up to 3 kJ of energy onto a flat region 600 m in diameter. The researchers used single-crystal natural Type-1a diamond discs and polycrystalline, synthetic Type-2a diamond discs created by chemical vapor deposition and having an average grain size of about 130 m with little preferred orientation. Any sample-type differences were well within our experimental uncertainties. The diamond’s density (0) and refractive index (n) at =532 nm were determined under ambient conditions to be 0=3.51(0.02) g cm3 and n=2.42(0.02).

Is it Possible for Diamonds to Melt in Lava?

Explained that a diamond cannot melt in lava because the melting point is approximately 4500 degrees Celsius (at a pressure of 100 kilobars). In contrast, lava can only reach temperatures of approximately 1200 degrees Celsius.

With Carbon imported from Russia. Galimov and colleagues recently published a report in American Mineralogist that describes the small diamonds they discovered in lavas from Tolbachik. Typically found in the rocks formed during the lava fountain phase of the eruption, these crystals are less than 0.03 inches in size and are less than 0.03 inches in diameter.

What is it that can Melt Diamond?

What is the temperature at which diamonds melt? As soon as you heat the diamond in the open air, it will begin to melt and burn at approximately 700° Celsius (1,292 degrees Fahrenheit). Burning a diamond in the absence of oxygen, on the other hand, will cause it to turn into graphite (a crystalline form of Carbon), which will then transform into a fluid.

It is possible to heat diamonds to greater temperatures when no oxygen is present. Diamond crystals transform graphite when exposed to temperatures higher than those specified below. The ultimate melting point is around 4,027 degrees Celsius (7,280 degrees Fahrenheit) for diamonds.

Is it Possible for the Sun to Melt a Diamond?

However, there is no need to be concerned about leaving a diamond in the Sun. Because the carbon atoms in a diamond are arranged in a tight, three-dimensional arrangement that is extremely difficult to disturb, it would take a 700-900°C before it starts to burn.

The Sun is surrounded by a blanket of plasma that stretches millions of kilometers into space. It can reach up to 3 million degrees Celsius in some locations (5.4 million degrees Fahrenheit). When exposed to such high temperatures, no known materials can exist as solids, liquids, or gases in their natural state.

Is it Possible to Burn a Diamond with Fire?

As a result of solid atomic bonds in diamond, it requires a significant amount of energy to break apart the carbon atoms in diamond to liberate them for use in combustion with air. As a result, a higher temperature is required to burn diamond than it is for burning wood. Wood has an ignition temperature of approximately 300 degrees Celsius, but the diamond has an ignition temperature of approximately 900 degrees Celsius in the air.

 Even though diamond requires a more significant temperature to burn, it does so through the standard carbon combustion process. With enough patience and the right circumstances, it is possible to burn diamonds in a standard flame with no special equipment. You may speed up the burning of a diamond by increasing the heat and the amount of oxygen it receives. For example, holding a blow torch to a diamond and then dropping it into a cup of liquid oxygen results in a visually stunning show of sparkle.

How do Diamonds Become Vapour if they are too Hard to Evaporate?

They begin to oxidize. Oxidation is a chemical reaction in which oxygen interacts with other chemicals and causes them to react. Oxygen makes up a significant portion of our atmosphere, and chemicals oxidize everywhere around us constantly. Rust, for example, is a product of the oxidation of ferrous materials, and rust is sometimes referred to as iron oxide in some circles.

Diamonds are a kind of pure Carbon that can be found in nature. As Carbon oxidizes, a chemical process occurs, resulting in the formation of the common gases carbon dioxide and carbon monoxide. These vapors form when a diamond is heated to such extreme temperatures.


Diamonds do not evaporate at high temperatures; they do not evaporate at all when the atmosphere is at an average level of pressure. Diamonds can only be heated to a greater temperature when there is no oxygen in the atmosphere. It is nevertheless feasible for diamonds to melt at a higher temperature than most other materials, even though the concept of a liquid diamond is debatable at best. Because Carbon is a gas, it can burn at significantly greater temperatures than those most other substances. When you burn a diamond in a Bunsen burner, the diamond will change into carbon dioxide, not a solid as is commonly believed. In the case of pure oxygen, the temperature will be in the vicinity of 600 degrees Celsius.

Carbon at high pressure is an essential component of planetary research, and it has the potential to be used as an ablator material in a future ion-bearing weapon design. Furthermore, it is a promising contender for use as a liquid ablator material in fusion weapons systems. However, the topic of diamond’s melting point remains unanswered. In any event, it’s still difficult to narrow down a precise temperature reading.