spinel
/spɪˈnɛl
/ /ˈspɪn(ə)l /noun [mass noun]
1A hard glassy mineral occurring as octahedral crystals of variable colour and consisting chiefly of magnesium and aluminium oxides.Legendary for its blood-red rubies and spinels, the Mogok stone tract of northern Myanmar also produces an amazing array of other minerals....
- Rubies were found in Burma and Ceylon, topaz, beryl, garnet, amethyst and pearl in Ceylon and Southern India, and spinels and deep blue sapphires in Afghanistan and Kashmir.
- His collection includes emeralds and spinels of a staggering size (some of them are nearly 300 carats).
1.1 [count noun] Chemistry Any of a class of oxides including spinel, containing aluminium and another metal and having the general formula MAl2O4.Examples of coexisting spinels in chemical equilibrium are uncommon at Hutter....
- UCLA's Kyte, who himself favored a fireball origin for the spinels, has measured the chemical composition of hundreds of spinel samples from around the world.
- At both Bald Knob and Hutter, rhodonite is absent in samples containing manganese spinels or manganese humites.
Origin
Early 16th century: from French spinelle, from Italian spinella, diminutive of spina 'thorn'.