Synthesis and Characterization of MgAl2O4 Spinel …

The synthesis reaction of magnesium aluminate spinel was complete at 800 °C.

Synthesis and Studies of Spinel Li2Mn0.5Ti0.5O3

This is one of the easiest of the synthetics to identify based on observation under magnification. And while the Chelsea filter is diagnostic for identifying synthetic blue spinel, neither the Chelsea filter or the spectroscope can be considered diagnostic for synthetic sapphires and ruby.

Synthesis of MgAl 2 O 4 Spinel Powder by Combination of Sol ..

The final is the spectroscope. There is so much chromium put into a synthetic flame-fusion ruby, that the chromium lines literally jump out at you. But again, you have to be experienced enough looking at chromium lines to know what you are looking at. So until you have looked at enough synthetic and natural rubies to know the difference, don't try to make this call on your own. Look for help from others more experienced.

The bottom line is, you are going to see a lot of flame-fusion synthetics out there. And they can range from rubies to sapphires to spinels and even to a vanadium doped corundum that emulates alexandrite. If you look for the curved striations, look for the gas bubbles, and the overall general perfection of the gemstones that just seems too good to be true....those will give you a good indicator of a flame-fusion synthetic gemstone.


Simple hydrothermal synthesis of mesoporous spinel …

The flame fusion process of creating synthetic gemstones was perfected in 1902 by a Frenchman named Auguste Verneuil. Also known as the Verneuil Process, this type of synthesis uses an aluminum oxide powder doped with trace elements to create synthetic corundum of various types. It is also used to make synthetic spinel, although not as much nowadays as it is used for corundum.

Synthesis of MgAl2O4 Spinel-Corundum Composite …

AB - Magnetic fine particles of cobalt ferrite (CoFe2O4) have been synthesized using complexometric method in which ethylene diamine tetra acetic acid C10H16N2O8 (EDTA) acts as a complexing agent. The crystallographic structure, microstructure and magnetic properties of the synthesized powder were characterized by using X-ray diffraction (XRD), particle size analysis and vibrating sample magnetometry (VSM). The material crystallized in cubic spinel structure with lattice parameter of about 8.38 Å. Depending on the calcining temperature, the particle size of the powders varies in the range of hundreds of nanometers to tens of micrometers. A desired relative density above 95% of the theoretical value is obtained for the bulk sample after sintering. The calcined powders and sintered sample exhibit saturation magnetizations around 80 Am2/kg which is expected for inverse CoFe2O4. With increasing calcining temperature the coercivity of these samples decreases. This simple synthesis route leads to a reproducible and stoichiometric material.

Synthesis of spinel-type lithium antimony manganese …

N2 - The process of producing spinel-type pigments from a mixture of Al 2O3 and Co2O3 with aluminum powder ASD-4 and MgO and ZnO additives by the method of self-propagating high-temperature synthesis (SHS) is investigated. A blue and an ultramarine pigment are obtained. Their phase composition, IR spectra, and structural and color characteristics are studied. It is demonstrated that the SHS method is promising for producing heat-resistant spinel-type pigments of a blue-sky-blue color range.

Molten salt synthesis of spinel-type LiTi 2 O 4 - JST

AB - The process of producing spinel-type pigments from a mixture of Al 2O3 and Co2O3 with aluminum powder ASD-4 and MgO and ZnO additives by the method of self-propagating high-temperature synthesis (SHS) is investigated. A blue and an ultramarine pigment are obtained. Their phase composition, IR spectra, and structural and color characteristics are studied. It is demonstrated that the SHS method is promising for producing heat-resistant spinel-type pigments of a blue-sky-blue color range.