There are at least 5 bands using the name Bloodstone

1 Bloodstone was a funk / soul / rock group formed in the 1960s in Kansas City, Missouri. Bloodstone was instrumental in the "black rock" and funk movement of the 1970's, and even had a hand in the brown-eyed soul movement with some Latin music-tinged hits.

Originally a high school doo-wop group, the members eventually moved to Los Angeles, California, learned to play instruments, and started a funk band. They became known for their funk / soul tracks that blended Jimi Hendrix-styled rock music with doo-wop and gospel music undertones. In 1973, Bloodstone's big label debut was an instant hit, with the single "Natural High" reaching the R&B Top Ten.

2 Bloodstone is a metal band from Singapore

Formed in 2004 and named after the Judas Priest song

Current Lineup:

Mike Destruction - Guitar / Vocals
Zeek - Bass
Cliff - Guitar
Jahannam - Drums

http://www.myspace.com/bloodstoneonslaught

3 There's another band called Bloodstone.
Bloodstone is a melodic hard rock band from Australia with 2 emigrants from Czech Republic formed by:

Zoran Grozdi - Vocals
Joe “Cool” La Ferlita - Guitar
George Harris - Bass
Vendula Kasparkova - Keyboards
Klaudius Kryspin - Drums

Bloodstone released an album called The Awekening in 1994 by Mediarex records.

4. The fourth band is a swedish Death Metal band called Bloodstone.They released a landmark underground death metal album in 1996 by the name of Hour of the gate,and split in the same year. They were formed in 1991. They also relased two demos before coming up with a full-length.

Last known line-up
Damien Hess - Vocals
Michael Samuelsson - Guitars
Svante Friberg - Bass
Mats Wikberg - Drums

5. The fifth band is a stoner metal/death metal four-piece from Corby, UK.