Fulgurite

Making Glass – Melting Sand with High Voltage Electricity!
Beals Science 2017
https://www.bealsscience.com/single-post/2017/02/14/Making-Glass-with-High-Voltage-Electricity-and-Sand

Making Fulgurites with High Voltage
The National Science Institute
http://thegeekgroup.org

Strangest Weather on Earth: Fulgurite
The Weather Channel

GCSE Science Chemistry (9-1) Diamond and silicon dioxide
Freesciencelessons 2016
https://www.freesciencelessons.co.uk/gcse-chemistry-paper-1

giant covalent molecules