spinel series

The spinel series refers to a group of mineral oxides with the general chemical formula AB₂O₄. In this formula, 'A' can represent elements like magnesium, iron, zinc, or manganese, while 'B' can be aluminum, chromium, or iron. The spinel group is further divided into three series: spinel (aluminum-spinel), chromite (chromium-spinel), and magnetite (iron-spinel).123

The spinel series specifically includes minerals where aluminum is the 'B' element. Key members are spinel (magnesium aluminum oxide), hercynite (iron aluminum oxide), gahnite (zinc aluminum oxide), and galaxite (manganese aluminum oxide). These minerals are typically found in igneous and metamorphic rocks. Gem-quality spinels, known for their resemblance to rubies, are often found in placer deposits.234