Ruri Rocks Episode 5 — Serpentinite Rocks!

Ruri Rocks Episode 5 was basically one big geology lecture, and I couldn’t be happier about it. While I firmly believe most educational systems are painfully flawed, I still think learning can be a fun experience when it’s done right. And Ruri no Hoseki nails it when it comes to making learning enjoyable.

Ruri Rocks Episode 5 — Worlds Seen and Unseen

Nine out of ten people agree that lab work is soul-crushing. The adorable Ruri finds herself in that majority. Shuffling through sand might lead Ruri to a sapphire, but hunching over a microscope will give her back pain and lifelong knee problems. So she convinces Nagi and Imari to go out with her and do some on-field rockhounding. And off they go—our geo-trio to a pebble beach and an exposed breakwater to hunt for agate. Being a slice-of-life, of course, they find what they’re after. They also stumble upon chalcedony—and, of course, the power of friendship.

The latter part of Episode 5 is dedicated to their search for platinum. It follows the same search methods we’ve seen before and proves quite fruitful. But what really made the episode sparkle (pun intended) was how Ruri and Nagi viewed what they were doing.

A Love for Geology

With every episode of Ruri Rocks, Studio Bind outdoes itself. Unless an anime is a TV original like Sorairo Utility, I rarely bother digging into the production staff. But I’ve eagerly searched for any info I could find about the people behind this series. I could write a whole book about the animation and production work in Ruri Rocks. But honestly, the real magic of this show lies in Nagi, and how she interacts with Ruri.

Nagi is a character that I love more with every appearance. Not only does she serve as Ruri’s mentor, but she genuinely rejoices when Ruri gets excited about what they’re discovering. There’s a deep affection and pride in her expressions whenever she manages to steer Ruri in the right direction. And in doing so, she’s the perfect guide—both for Ruri and for us—to a deeper appreciation of geology and mineralogy.

At the start of this article, I mentioned I’m one of those who firmly believe current educational systems are failing students. There are many reasons for that, but the biggest one is simple: most schools emphasize memorization and repetition rather than encouraging problem-solving and curiosity.

If you really want people to get invested in something, appealing to their curiosity is the way to go. Relying on memorization and repetition often results in tunnel vision; when something outside that curated knowledge appears, frustration sets in. That frustration can quickly turn into disinterest. But when someone develops a real interest and curiosity about a subject, they’re more likely to challenge any barriers between them and the knowledge they seek. That’s exactly what Nagi does in Ruri Rocks: she’s there to spark curiosity in both Ruri and us, igniting that drive to learn.

The Mineral Corner

While Ruri Rocks Episode 5 focused on agates, serpentinite, and platinum, I have no practical experience with any of those. So, instead, let me share a bit more mineral knowledge to fill your brain.

Although Ruri Rocks associates platinum with serpentinite, their connection isn’t that common. You might find them together sometimes, but serpentinite isn’t a primary host rock for platinum. So, what exactly is serpentinite? It’s a metamorphic rock—more specifically, it’s undergone the process of serpentinization.

Serpentine minerals—like antigorite, brucite, magnetite, and others—are classified within this group. As the show mentions, serpentinite is common around tectonic plate boundaries. From a geological perspective, serpentinite is pretty fascinating. Well, the process that creates it is interesting because it produces acetyl-CoA, a key molecule in the origin of life. Some scientists even speculate that life may have begun in serpentinite thermal vents.

Ironically, asbestos (chrysotile) also originates from serpentinite, which can be a problem for amateur rockhounds. Someone unfamiliar might pick up a strange-looking rock or break off a piece without realizing the dangers involved.

For anyone into botany, serpentinite environments are home to some of the most unique plants on Earth. Because serpentine soils are low in nutrients, they give rise to a surprisingly high number of plant species that are found nowhere else—serpentine endemics. But while I’ll gladly talk about the mineralogy and geology aspects of Ruri Rocks, epsiode 5 I’ll leave the botany lesson to some angry guy from Chicago. Until next week—ja ne!

Screenshots via Crunchyroll
©Keiichiro Shibuya/KADOKAWA/”Ruri’s Jewels” Production Committee