Ep. 7: Shoko finds friends while exploring sea glass and silica color science with Ruri.
Aired on August 17, 2025
7
Schoolgirl Shoko has a passion for rocks but lacks support until she meets Ruri and her group, who are investigating sea glass. The episode explains how silica glass acquires different colors, specifically through the phenomenon of thin-film interference. During a day spent searching for old bottles on the beach, Shoko makes new friends who share her interest. Additionally, Ruri discovers that her name is an archaic term for blue glass, adding a personal layer to the day's discoveries and strengthening the bond between the characters.
Episodes
- Ep. 3 · Nagi and Ruri explore a university lab and discover a mysterious bismuth crystal alongside an old map.
- Ep. 4 · Ruri uses magnetism to accelerate sapphire source analysis while Yoko studies fluorites.
- Ep. 5 · Ruri, Yoko, and Nagi explore a gravel beach for rocks and minerals.
- Ep. 6 · Ruri and friends locate the sapphire deposit after correcting a note error near a shrine.
- Ep. 7 · Shoko finds friends while exploring sea glass and silica color science with Ruri.
- Ep. 8 · Shoko and Ruri investigate water quality and discover orange crystals at an abandoned factory.
- Ep. 9 · Team discovers opals at dam after investigating riverbank waste and quartz sources
- Ep. 10 · Geologists explore abandoned manganese mine and discover toxic rhodonite ballast
- Ep. 11 · Ruri uses gem analysis to resolve her course selection dilemma