http://breezewiki.catsarchywsyuss6jdxlypsw5dc7owd5u5tr6bujxb7o6xw2hipqehyd.onion/minecraft/wiki/Glowing_Obsidian
Glowing obsidian turns into obsidian after a short amount of time. Glowing obsidian has the same blast resistance as normal obsidian. If the nether reactor core is mined out while the nether reactor was active, the glowing obsidian won't turn into obsidian after the reactor is deactivated.