Complex sentence: Fulgurites are a variety of the questionable mineral lechatelierite (from the Latin "fulgur" meaning thunderbolt) are natural hollow glass tubes formed in quartzose sand, silica, or soil by lightning strikes.
Split into simpler sentences: Fulgurites are a variety of the questionable mineral lechatelierite (from the Latin "fulgur" meaning thunderbolt). They are natural hollow glass tubes formed in quartzose sand, silica, or soil by lightning strikes.