1. A brownish-black mineral form of uranium oxide that is the primary ore of uranium and radium.
Usage: geology; mineralogy

Examples

• Pitchblende was the source material from which Marie Curie isolated radium.
• The pitchblende deposits in the Congo were historically important for uranium mining.
• Scientists discovered that pitchblende contained previously unknown radioactive elements.
• Pitchblende's high uranium content made it valuable for nuclear fuel production.
• The dark, dense pitchblende ore was refined to extract pure uranium.