One of the March Birthstones is Bloodstone
Two very colorful pieces of the March birthstone. These specimens have a white crystallized section surrounded by dark red and many green speckled hues. 
Heliotrope is the traditional birthstone for March and has been replaced by aquamarine. However, bloodstone is still regarded as the astrological gem for Aries. Bloodstone is also called heliotrope. It comes from the Greek “helio” and “tropos”. The red inclusions are supposed to resemble spots of blood; therefore the name "bloodstone" has been adopted.
The characteristics of Bloodstone
As a formation of chalcedony the "classic" bloodstone is green chalcedony with red inclusions of iron oxide or red jasper. The green color is due to the presence chlorite. The color varies and some samples of bloodstone have very few or no red spots.
- Adapted form work By Adam Ognisty (Own work) [CC BY 3.0], via Wikimedia Commons
- By Ra'ike (see also: de:Benutzer:Ra'ike) (Own work) [GFDL, CC-BY-SA-3.0 or CC BY 2.5], via Wikimedia Commons
- By Ra'ike (see also: de:Benutzer:Ra'ike) (Own work) [GFDL or CC BY-SA 3.0], via Wikimedia Commons
- By Adam Ognisty (Own work) [CC BY-SA 3.0], via Wikimedia Commons