Diamond face shape
Cheekbones form the widest point.
How to recognize the outline
Move hair away from your temples and trace down toward the chin. The diamond sketch opens out at the cheekbones and narrows both above and below them. If one cheek looks much wider in a single picture, check a level view before drawing the outline.
Diamond or heart?
Compare the temple line to the cheeks, ignoring your hair volume. In a heart shape the upper face usually carries more of that width. In a diamond sketch the outer cheeks are the clearest turning points. See the heart sketch.
What to check when trying glasses
Check lower-rim clearance against each cheek while smiling. Compare an upswept corner with a level brow at the same width; watch whether your eye goes first to the outside corner or to the cheek line.
A haircut trial in the mirror
Keep one side tucked and release the other near the temple. Swap sides before deciding. This lets you see how exposing the cheekbone differs from adding softness above it, using the hair you already have.
Compare your outline in the free face shape finder or ask friends to choose between two of your looks.