Was with customers most of the day. Looks like a snap snap you got there! I am not a metallurgist but I am a degree'd chemist with an advanced degree in engineering, that and 0.50 will get you a cup of coffee! Now, back to the matter at hand. Looks like a great example of brittle fracture to me - great image of the crystal structure and no signs of necking (elongation).
This is Ductile Fracture and this is Brittle Fracture
