glass-like carbon

https://doi.org/10.1351/goldbook.G02639
An agranular @N04194@ with a very high isotropy of its structural and physical properties and with a very low @P04503@ for liquids and gases. The original surfaces and the fracture surfaces have a pseudo-glassy appearance.
Note:
The often used synonyms 'glassy carbon' and 'vitreous carbon' have been introduced as trademarks and should not be used as terms. From a scientific viewpoint, all synonymous terms suggest a similiarity with the structure of silicate glasses which does not exist in glass-like carbon, except for the pseudo-glassy appearance of the surface. Glass-like carbon cannot be described as @A00294@ because it consists of two-dimensional structural elements and does not exhibit 'dangling' bonds.
Source:
PAC, 1995, 67, 473. (Recommended terminology for the description of carbon as a solid (IUPAC Recommendations 1995)) on page 490 [Terms] [Paper]