New shapes? They're "growing" diamonds that are faceted already? Or am I misunderstanding something here?
The grown diamond grows in the same shape as the 'seed diamond'. You're not misunderstanding.
This photograph shows a synthetic brilliant cut single-crystal diamond grown by chemical vapor deposition, CVD. About 2.5 mm high, this crystal was grown in about 1 day at Carnegie. The very bottom (table) of the crystal is a type 1b seed: hence the yellow tint which is due to internal reflection (the CVD diamond is transparent...
More info here: Link