Which term refers to a flat, triangular twinned diamond crystal?

Which term refers to a flat, triangular twinned diamond crystal?

• A. Grain lines
• B. Habit
• C. Macle
• D. Twinned crystal

Answer: (A)

In diamonds, a flat, triangular twinned crystal is called a macle. A macle forms when two or more crystal segments grow together on a twin plane, producing a thin, flat piece with a triangular or rhomboidal outline that looks like a single joined crystal. This distinguishes it from grain lines, which are internal growth marks within a crystal; habit, which refers to the general crystal shape a diamond tends to take; and twinned crystal in a general sense, which just means the crystal has undergone twinning without specifying the flat, joined appearance of a macle. So the specific term for that flat, triangular twinned form is macle.

In diamonds, a flat, triangular twinned crystal is called a macle. A macle forms when two or more crystal segments grow together on a twin plane, producing a thin, flat piece with a triangular or rhomboidal outline that looks like a single joined crystal. This distinguishes it from grain lines, which are internal growth marks within a crystal; habit, which refers to the general crystal shape a diamond tends to take; and twinned crystal in a general sense, which just means the crystal has undergone twinning without specifying the flat, joined appearance of a macle. So the specific term for that flat, triangular twinned form is macle.