Post by account_disabled on Mar 6, 2024 9:05:32 GMT
Treatment that we can observe are the following: Microscope Photo 2: microscope. Author: Gómez Altered crystals: crystals with a tensional halo around them or a matte edge are observed, giving a characteristic atoll shape in many cases. This type of inclusion is telling us that the crystal is altered and, therefore, is clear evidence that the gem has suffered heat (photo 3). Crystals and veils altered by an increase in temperature in treated corundum Photo 3: Crystals and veils altered by an increase in temperature. Author: Almudena Gómez Altered veils: if we see veils that have a matte edge, it is also indicative of heat treatment. Rapid cooling points : when a sapphire is subjected to an increase in temperature, it then cools rapidly and results in the alteration of veils, causing whitish points to form. These rapid cooling points sometimes form structures that remind us of fingerprints .
Fingerprint-shaped inclusion in corundum Photo 4: fingerprint. Author: Dissolved rutile needles: rutile needles (TiO2) are very delicate and begin to dissolve at temperatures that are not very high. If we observe rutile dust or silks, it indicates that this dissolution has Cell Phone Number List occurred and is evidence of heat treatment. “Ink Spots” or ink dots: they are due to a process called internal diffusion, which is not the same as the thermal diffusion process. Rutile needles take a long time to form in nature and when they are subjected to an increase in temperature, they dissolve and when cooled again, they no longer precipitate the same since the formation process is much faster and instead of forming needles of rutile, ink dots and lines called “ink spots” are formed (photo 5). “Ink spots” in heat-treated sapphire Photo 5: “Ink spots” in heat-treated sapphire.
Author: Gómez If we observe one or more of the above inclusions, we are looking at a corundum with evidence of heat treatment. There are other somewhat more complex and combined treatments such as heat and fissure healing with borax, which are also considered thermal treatments, but their procedure is more complex and they must be studied separately. It should be noted that it is not always possible to easily detect a heat treatment because it may have been carried out at less than 1300ºC and is barely detectable. To determine a thermal treatment, in many cases, a study with advanced analysis techniques, such as spectroscopies, is necessary. Spectroscopic techniques are based on observing the response of a material when one or more wavelengths of the electromagnetic spectrum are incident on it. Infrared spectroscopy (FTIR) , for example, is very useful to determine evidence of heat treatment in sapphires of metamorphic origin.
Fingerprint-shaped inclusion in corundum Photo 4: fingerprint. Author: Dissolved rutile needles: rutile needles (TiO2) are very delicate and begin to dissolve at temperatures that are not very high. If we observe rutile dust or silks, it indicates that this dissolution has Cell Phone Number List occurred and is evidence of heat treatment. “Ink Spots” or ink dots: they are due to a process called internal diffusion, which is not the same as the thermal diffusion process. Rutile needles take a long time to form in nature and when they are subjected to an increase in temperature, they dissolve and when cooled again, they no longer precipitate the same since the formation process is much faster and instead of forming needles of rutile, ink dots and lines called “ink spots” are formed (photo 5). “Ink spots” in heat-treated sapphire Photo 5: “Ink spots” in heat-treated sapphire.
Author: Gómez If we observe one or more of the above inclusions, we are looking at a corundum with evidence of heat treatment. There are other somewhat more complex and combined treatments such as heat and fissure healing with borax, which are also considered thermal treatments, but their procedure is more complex and they must be studied separately. It should be noted that it is not always possible to easily detect a heat treatment because it may have been carried out at less than 1300ºC and is barely detectable. To determine a thermal treatment, in many cases, a study with advanced analysis techniques, such as spectroscopies, is necessary. Spectroscopic techniques are based on observing the response of a material when one or more wavelengths of the electromagnetic spectrum are incident on it. Infrared spectroscopy (FTIR) , for example, is very useful to determine evidence of heat treatment in sapphires of metamorphic origin.