amnhnyc: This spectacular pillar of labradorite rock formed as magma intruding into the Earth’
amnhnyc: This spectacular pillar of labradorite rock formed as magma intruding into the Earth’s crust cooled, some 660 million years ago. It comes from a large body of anorthosite, a type of igneous rock. Notice its blueish-green shine? Its glisten is a result of its iridescence! The block’s iridescence is due to light scattering from submicroscopic layers with different chemical compositions, which separated from one another as the minerals cooled. See it up close in the new Mignone Halls of Gems and Minerals, now open! Access to the new Mignone Halls of Gems and Minerals is included with General Admission to the Museum. With limited capacity, all visitors will be required to join a virtual line (once at the Museum) for entry. For more details, please visit the #linkinbio. Photo: D. Finnin/© AMNH #NewYorkRocks (at American Museum of Natural History)https://www.instagram.com/p/CQFc-fWAjbC/?utm_medium=tumblr -- source link