I don't have a Wikipedia link for this material, because it hasn't been written yet. I did find a nice article written about it here (scroll down a little), & a page about its metaphysical properties here, if you're into that kind of thing.
I can tell you that in addition to being very beautiful, it's also very soft, measuring about 2.5 on the Mohs scale (with talc measuring 1 & diamond measuring 10), so if you sometimes nibble on pens or other objects, you should be very careful with this one.
Each nugget is about 8 to 13mm in length, & linked with tarnish-resistant silver-plated wire. I used a silver-plated hook & eye clasp. It's a very long necklace, about 28.5 inches (can be worn shorter by hooking the hook between two beads). The weight is 1.4 oz.
Price: $35 (shipping is free)