I had to repin this pic of round stones. Not just because the imagery is cool but tempted to pin under geek category... reminds me of a sci-fi - invasion of the aliens or something. Maybe these are Tribble eggs? Too geek? LOL
Pegmatite is very crystalline, an intrusive igneous rock composed of interlocking crystals usually larger than 2.5 cm; such rocks are referred to as pegmatic. Most pegmatites are composed of quartz/ feldspar/ mica; e.g. granite.
Pegmatite is a light-colored, extremely coarse-grained intrusive igneous rock. It forms near the margins of a magma chamber during the final phases of magma chamber crystallization. It often contains rare minerals that are not found in other parts of the magma chamber. The specimen shown above is about two inches (five centimeters) across.