What do CVD diamond rough resemble?

• A. Slabs with a square cross section.
• B. Spherical chunks.
• C. Irregular amorphous lumps.
• D. Fibrous crystals.

Answer: (A)

CVD diamond rough tends to form flat, plate-like slabs because growth happens on a flat seed surface and proceeds in layers on a broad plane. This creates crystals with broad, flat faces and a roughly square or rectangular cross-section when viewed along certain axes, so the rough resembles slabs rather than rounded or irregular shapes. A spherical chunk would imply growth in all directions without a preferred plane, which isn’t how CVD crystals typically develop. Irregular amorphous lumps would indicate non-crystalline carbon rather than crystalline diamond. Fibrous crystals describe elongated, needle-like forms not characteristic of the common plate‑like CVD growth.