Pretty hard to give an exact possible location with such a small specimen I’m afraid. To my eye it looks like it may have come from the Marsden area.
A piece I picked up. Laying in the sand with some of the rind showing and boot prints all around it
This stone was found up the Arahura River. As you can see it is full of belts of different coloured hues. Not exactly a beautiful specimen but as a very knowledgeable and experienced person told me, “You would be extremely hard pushed to find another example like this”. As you can see from the picture. It is a mix-mosh of all the typical Greenstone colours. Arahura stone is traditionally a deep emerald (Nephrite) green. Greenstone from Fiordland/South Westland is known for its deep blue/green (Bowenite) coloration. And as mentioned Marsden Stone having the hue similar to the pic you provided.
Hope this helps.