I have been fortunate enough to receive a bottle of J Herbin 1670 Emerald of Chivor to review. It's my understanding that it's due to be released in August.
So I'm going to write with it over several days and post my experiences on this thread.
I have filled my Pilot Custom 74 M nib with it so far, so this is the pen I'm using today. However, I can easily change that M nib to a F one from my CH92, so I plan to do that as a comparison. Then I will use a different pen and nib type.
First things first, this ink oozes quality. It feels beautifully smooth and lubricated from the pen. It is very saturated and shows lots of different shading, as well as it's sheen. In my opinion it isn't what I would call an emerald colour, as I think of emeralds as a vibrant green. This ink is teal blue-green. When I started writing with it I thought I must compare the colour to that of Sailor Yama-dori, so that's something I will add over the course of the next few days.