34. Pegmatites Dan Barker April 2009 Pegmatites are coarse- grained rocks. Most are granitic. 2-meter long quartz and K-feldspar crystals, Althaus pegmatite, Llano Uplift, TX

Layers in Althaus pegmatite, TX

Coarse core below layers, Althaus pegmatite, TX

"Line rock" in pegmatite, Ramona CA

False cleavage in quartz core of pegmatite, Pala, CA

Pegmatite and schist, Pemaquid Point ME

Pegmatite at contact of Port Mouton granite pluton, Nova Scotia

Pegmatite/gneiss contact, Palermo NH

Pegmatites in the Painted Wall, Black Canyon of the Gunnison River, CO

Crossing pegmatites, Westerly granite, RI

Pegmatite offset by a dike of "aplite" (fine equigranular light- colored granite), Sparta, GA

Small systematically offset pegmatite in Valley Spring Gneiss, Inks Lake State Park, TX

Quartz core and large K-feldspar crystals in pegmatite, Inks Lake State Park, TX

Intersecting pegmatites, Wausau WI

Not all pegmatites are granitic. This one consists of sodic clinopyroxene and alkali feldspar. Nevlunghavn, Norway.

The gabbro pegmatite (plagioclase and pyroxenes) on the right is in a thick basalt flow, Mt Pleasant quarry, NS

Gabbro pegmatite with sulfides (arrow), Port Coldwell Complex, ONT

Pegmatite (plagioclase and clinopyroxene) Port Coldwell ONT

Another weird pegmatite from the Port Caldwell complex. The red is altered iron-rich olivine; the rest is plagioclase.

Another from the same place; plagioclase and blue amphibole.