Fiber optic cable and viscous filler material

A fiber optic cable assembly comprising:

• (a) at least one optical fiber;
• (b) a sheath longitudinally surrounding and substantially concentric with said optical fiber;
• (c) a grease in contact with said optical fiber and said sheath, said grease comprising a diamondoid component which has been processed to remove at least a portion of organics having fewer than 10 carbon atoms, said diamondoid component comprising at least about 65 weight percent alkyl-substituted diamondoid compounds;
• and a thickener component which is substantially inert to said sheath.