Found this near the Shannon River close to Carrick on Shannon Irelandenter image description here Could this be Mutton Fat Nephrite Jade? Thank you
Your rock is composed mostly of quartz based texture of the rock's surface and color. It is not jadeite nor nephrite. Mutton fat jade is typically more pale yellowish in color.
Your rock looks very much like Dallasite which is a rock formed from Chlorite, Quartz, and Epidote. It is very common on Vancouver Island but I also suspect it can be found in other areas with pillow basalts. It is a breccia of the minerals above formed primarily from the outer portions of the pillow basalts. I have seen Dallasite deposits in situ that appear to fit in the small void between various balsalt pillows but I cannot seem to find the photos I took. A quick search on "Dallasite in BC" on Google will show a number of different images looking similar to yours. Your rock appear to be heavy towards the quartz but otherwise looks like Dallasite I have seen. The description in Wikipedia is correct if somewhat brief. Dallasite described in Wikipedia
The name "Dallasite" is likely a local name from the Vancouver Island area, other locals make give this rock a different name.