| This substance is almost unknown in a pure state, from its extreme proneness to absorb oxygen and pass into the sesquioxide. |
| In these soils, red iron and aluminum hydroxide and sesquioxide compounds, the residual products of rock decay, have accumulated. |
| The dichromate is then reduced with carbon to chromium sesquioxide, Cr2O3, and that oxide in turn is reduced with aluminum to give the chromium metal. |
| The rare metal iridium affords a blue which is a mixture of the oxide and the sesquioxide. |
| The sesquioxide is found crystallized in an anhydrous form in braunite, and hydrated in manganite. |
| Pass dry chlorine over a mixture of sesquioxide of chromium and charcoal, heated to redness, in a porcelain tube. |
