At least 17 distinct lava events are known to have flowed through central Washington, creating the layers of jagged backdrop behind this lonely canoer at Columbia Wildlife Refuge [Nick Zenter, Sand Hill Crane Festival, 2017]. There's lots of reasons to love lava, but where there is lava, there are fun metamorphic rocks! And volcanoes. And volcanoes kill people, so I will start with them.
Historically, that's just a thing volcanoes known for. Barfing up rolling waves of ash and searing mud that fills the atmosphere, sophisticating flora of sunshine and melting peoples' faces off like soft cheese on a Missouri sidewalk. The globe spins into catastrophe while the earth scientists patiently remind us all that it's no big deal. Is this because they are the ones who see it coming? Probably, although I'd rather not disregard the many volcanologists lost to eruptions and invisible sulfur pockets. Among the animals, humans are that delightful combination of aware-enough-to-see-it-coming and still doomed-to-succumb-to-it. An early geology class told me as much, "Be careful, I know it sounds fun to explore volcanoes, but even the docile volcanoes in Hawaii still kill the scientists studying them. It's much safer to be a geologist for the developers on the other islands." Most enlightening for a 6th grader. Thank you, Mr. Tall Middle School Teacher with the Transformer Action Figures in the Window.
Volcanoes also happen to be the traditional stomping grounds for human development and discovery. It doesn't hurt that all land is some form of magma coming to the surface, so this is a blanket statement in the most extreme sense. Rockhounding is notorious for seeking out young-earth (how I think of volcanic regions) patches to scavenge for strangely arranged crystals resulting from volcanic activity.
Of the many goodies growing out of lava pockets, obsidian is a commonality. My pocket rock guide [Washington & Oregon Rocks & Minerals by Dan R. Lynch & Bob Lynch, page 187] has the following to say on obsidian, "...it formed from molten *rhyolite and cooled before the minerals within could crystallize, instead hardening as a jumble of molecules....in the Pacific Northwest obsidian typically formed when highly viscous (thick, sticky) rhyolite lava rich with silica (quartz material), but almost devoid of water, cooled as a large mass." What is essentially nature-made glass has adopted a variety of colors, shapes, and mythological associations. Here, I will discuss two of these: Apache tears [Figure 2] and obsidian spears [Figure 3].
Obsidian is usually associated with bad juju, so the racially inappropriate name of Apache tears isn't all that surprising. Obsidian spears are also easily villianized as they are opaque, pointy, and scandalously colored. Like a deal with the Devil, obsidian is alluring and brittle, it promises much and deliveries almost nothing in the way of practicality. According to my home guide [Simon & Schuster's Guide to Rocks and Minerals, 2003 edition, section 314], it's been a spell since the last time obsidian was regularly circulated in tools. It was "used in prehistoric times for tools and sculptures. Currently used industrially as raw material for rock wool." And there you have it. This extrusive igneous rock's greatest asset is to stuff the walls of music rooms as a sound-reducer. Although, Wikipedia says it can also be an integral part of filters for hydroponic growth systems. There's a nifty tidbit (I'm learning so much).
Obsidian crystals sometimes form in little orbs, bubbles of material if you will, along basalt or other bedrock [Figure 2]. When they break off, you're left with black glass pebbles dotting the landscape. In the southwest, which is rife with decomposing volcanoes, some poor schmuck thought to name these stones Apache tears. I looked up the story behind the name, and paraphrased it as follows, according to one source:
"[It is] the story of 75 brave Apache warriors who were camped on a mountain, and who were attacked by soldiers of the U.S. Cavalry. In the sneak attack, 50 of the Apaches were killed within minutes, while those that remained retreated to the edge of a cliff. Realizing that they had nowhere to go, the remaining warriors chose to leap to their death, rather than to die at the hands of the white man. When the women and children discovered their beloved husbands, fathers, and sons dead at the bottom of the cliff, they began to weep. And as their tears fell, black stones were formed on the white, sandy earth for every tear that hit the ground. These are Apache Tears. Legend has it that anyone who has any of [these] stones... should never need to cry again, because the Apache women cried enough tears for all who mourn. Some believe that the stones themselves carry spiritual and healing powers."
[2013. The Legend of Apache Tears. Na