Spinel - Wikipedia
Spinel (/ spɪˈnɛl, ˈspɪnəl / [7]) is the magnesium / aluminium member of the larger spinel group of minerals. It has the formula MgAl. 4 in the cubic crystal system. Its name comes from the Latin word spinella, a diminutive form of spine, in reference to its pointed crystals. [5]
inclusion in spinel - SpringerLink
inclusions in spinel are less common than in other similar stones like ruby or sapphire. Rarely there are silk inclusions, and angular inclusions that are called spangles, which are inclusion crystals with iridescent stress features surrounding the inclusions.
Spinel group - Wikipedia
Spinels commonly form in high temperature processes. Either native oxide scales of metals, [18] or intentional deposition of spinel coatings [19] can be used to protect base metals from oxidation or corrosion.
Iridescent Spindle (Ioun Stone) - d20PFSRD
Cracked: This stone grants a +4 competence bonus on Constitution checks to hold your breath. Price: 500 gp. Flawed: This stone sustains the wearer without air, but he is always staggered. Price: 12,000 gp. See Inferior Ioun Stones for details on cracked and flawed variant stones.
Spinel: Mineral information, data and localities. - mindat.org
Spinel: Mineral information, data and localities. Spinel-Hercynite Series, Gahnite-Spinel Series, and the Magnesiochromite-Spinel Series. Intensely coloured varieties due to the incorporation of various ...
Spinel - The Gemology Project
2012年8月17日 · Spinel is allochromatic and variety colors are produced by transition metals: Transparent to opaque. Spinel is isotropic and the refractive index of common spinel is generally around 1.712 to 1.720. Red spinel can have a refractive index up to 1.74.
Spinel Description - GIA
Spinel offers a range of hues, from orange to intense “stoplight” red, vibrant pink, and all shades of purple, blue, and violet through bluish green. Intense reds and pinks are caused by traces of chromium. The higher the chromium content, the stronger the red hue. Orange and purple stones owe their color to a mixture of iron and chromium.
16.13: Spinel - Geosciences LibreTexts
Spinel is allochromatic and variety colors are produced by transition metals: Transparent to opaque. Spinel is isotropic and the refractive index of common spinel is generally around 1.712 to 1.720. Red spinel can have a refractive index up to 1.74.
Spinel thin section - Non-silicates - MicROCKScopic
Spinel thin section photomicrographs are taken in plane-polarized light and cross-polarized light, and can easily be recognized under the microscope.
Gray Spinel: A New Trend in Colored Stones | Gems
2019年5月15日 · Gray spinels were one of the obvious new trends at the Tucson shows this year. It was not hard to find exhibitors showing off their gray spinel, and everyone who had them commented on how quickly they were selling.