This is a superbly formed example of impact glass/tektite because it is a real specimen, with "pseudocrystals" that look like crystals although they are formed as the melted impact debris congealed more like a glass process. The individual arms of this specimen diverge from a center point just like a droplet of water when it hits a solid object. Individual arms reach 7 mm in length and are lustrous and translucent. The color is a eye pleasing medium green, similar to that of ludlamite. It is just so special, amidst so many amorphous blobs of this material, that I thought it worth buying when I saw it for sale (at a mineral show in China, believe it or not) as one of the few specimen-worthy examples of this species I have seen in years. More about this natural oddity, which is a prized meteoric-origin gemstone: https://en.wikipedia.org/wiki/Moldavite