Speaking to Guitar World, Iommi referred to the Van Halen founder as one of his "two really great friends in the music business", and goes on to tell the story of their relationship.
The two bands first played together on Van Halen's 1978 World Tour, when Van Halen supported Black Sabbath at 20 UK shows and at over 50 shows in Europe and North America.
"It was the band’s first world tour and we were on the road together for several months," says Iommi. "We had such a great relationship.
"I used to see Eddie most nights after the show either in my room or his room or in the bar or whatever. We used to just chat all bloody night, and he’s been a really great friend to me ever since. We just talked a lot about music, guitars and the business, really, because Van Halen were fairly new into the business. And sometimes he’d bring his guitar around to my room and we’d play for a bit.
"I first heard him on the tour, and I thought, “What?!?!” His energy and persona stood out immediately. You could see he loved playing and was brilliant at it. It was the first time I’d ever heard his various techniques, and he just got better and better as his time went on. I’ve always had great respect for his playing. Van Halen were a bloody hard act to follow, but we worked as a team."
Iommi also talk about their more recent relationship, about Van Halen's struggle with arthritis, and about both musician's approach to playing guitar. Read the full feature.
In the months since Van Halen's death, musicians including Slash, Kirk Hammett and Tom Morello have paid tribute to the guitarist, while Eddie's son Wolfgang released his own emotional tribute, Distance.
“I never intended Distance to be the very first piece of music people would hear from me," said Wolfgang, "but I also thought my father would be here to celebrate its release.
“As my pop continued to struggle with various health issues, I was imagining what my life would be like without him and how terribly I’d miss him. While the song is incredibly personal, I think anyone can relate to the idea of having a profound loss in their life. This is for him. I love and miss you, Pop."