Cocoa shimmer by Diamine is a brown color with gold shimmer. It's part of the Diamine shimmer collection. Unlike other shimmering inks this one actually has significant shimmer but it's hard to bring it out on scan or camera. On paper the gold is clearly visible though. A beautiful effect but you don't want to use this ink anywhere. I wouldn't use it in the office, not even for personal work notes. Especially for cards and letters it is excellent. The brown is beautiful and deep. But you can do your personal writing with this color easily, even with long pieces it remains pleasant to read.
The ink is very well behaved, but on the wet side. Drying time is very high (68 seconds on Rhodia paper). But lubrication is very well, the show-through is minimal and shading is nice and subtle. The shimmer is clearly visible.
The ink is quite red and saturated, which is clearly visible when you compare swabs of cocoa shimmer with yama-guri (Iroshikuzu). Herbin's Caroube de Chypre comes close, but has a silver shimmer.
All in all this is a very nice ink and a welcome addition to my collection. I will definitely use it from time to time for cards and shorts letters.