Two-dimensional transparent muscovite flakes, a mineral in the mica family, were once formed in layers on the seabed and decorated with the cliffs and peaks of the mountains and the rocks of the Bath Creek basin. Iron-dyed schist, a coarse-grained rock made of potash feldspar and quartz, happily flaunts muscovite flakes on its orange surface, as if they were diamonds.

Clusters of arrow-leaf balsam and large pieces of heart-leaf arnica are yellowing under the towering yellow pine. They clamored for my attention, but the stone won! I can only take a few steps before stopping to pet and examine another shiny specimen. After months of social distancing, I came to photograph wildflowers and escape the walls of the apartment, but the gleaming rocks held my breath. I have to touch each one. I even took some home.

    The mirror minerals on the creeks and trails gleamed in the bright sunlight. I spent five hours exploring the 5-mile section of the Bass Creek drainage system in the lower Bitterroot Mountains. The rock cast a spell on me. If I don't stop and observe carefully, I won't be able to pass. I squatted and crawled in the dirt, marveling at the glitter, texture and color. Unlike flowers, each rock is different from the next—they tell the story of how the earth works.

    Once upon a time, the waters of the Pacific Ocean met the land of western Idaho. About 100 million years ago, the North American tectonic plate moved westward and collided with the abundant rock-forming minerals that make up the seafloor. The collision pushed the ocean slabs down into the earth’s hot mantle and into the lava cauldron. The liquefied rock rises and cools the granite that formed the bedrock of Idaho, an igneous rock mass of quartz, quartzite, feldspar, and mica that extends from what is now central Idaho to southwestern Montana.

    The plates continued to migrate, and the earth bulged upward to form the Kugen Mountains. Rocks are crushed, folded and broken by heat and friction. It metamorphoses into quartzite and schist. After another 40 or 50 million years, the top layer of sediment slipped eastward, forming the Sapphire Mountains and the Bitroot Valley in the middle. About 12 million years ago, flowing glaciers carved, collapsed and eroded the uplifted mountains in the west, forming the drainage system of the Bitterroot Mountains today, providing multiple paths into the Selve-Bitterroot Wilderness. The largest wasteland in the 48 contiguous U.S. states.

    Two-dimensional transparent muscovite flakes, a mineral in the mica family, were once formed in layers on the seabed and decorated with the cliffs and peaks of the mountains and the rocks of the Bath Creek basin. Iron-dyed schist, a coarse-grained rock made of potash feldspar and quartz, happily flaunts muscovite flakes on its orange surface, as if they were diamonds. The gleaming schist in my hand was crushed, crushed and heated by the friction of the moving earth and the hot magma.

    When humans first discovered that light can pass through these thin transparent layers, muscovite was made into windows. Today, it provides luster to paints, glazes and cosmetics. Unfortunately, illegal mica mining and poor supervision have led to the collapse of Indian mines, and lung diseases have claimed the lives of many Indian child laborers. In 2017, a global alliance established a fair and sustainable mica supply chain and formulated policies to improve working conditions in Indian mines and eliminate child labor.

    On the sidewalk beside me, chatting women passed by on horseback. They turned a blind eye to shiny things. Sweaty cyclists and runners focus on their physical goals and challenges. The mother calls to the stray children, and the father calls to the stray dogs. I wade among the gleaming muscovite in the creek, immersed in beauty and history. A crystal window opened. I heard the sound of a gentle and silent mineral, and I went deep into the gleaming antiquity.

"Field Notes" is produced by the Montana Natural History Center.

(Broadcast: "Fieldnotes", 6/29/21 and 7/2/21. Listen on the radio at 4:54 pm on Tuesdays and Fridays, or listen through podcasts.)