A fire cloud or pyrocumulus cloud is consists of a dense cumuliform cloud with volcanic or fire activity. It is produced by intense temperature in the air surface. The heat triggers convection causing the air mass to rise. Phenomena like forest fires, industrial activity, and volcanic eruption causes the formation of this cloud.
Shelf cloud is a wedge-shaped and low-lying arcus cloud which is attached underneath of the parent cloud. It is usually seen on the leading edge of a storm or gust front. People find shelf clouds as a stunning feature of summer and spring time thunderstorms.
Roll cloud is a tube-shaped horizontal cloud known for its solitary wave. This type of cloud is formed by outflows of cold breeze or cold fronts. Though they form along the gust front, it does not produce tornadoes.
Cloud iridescence are similar on the oil films you’ve seen on puddles. Most of these clouds are observed in lenticular clouds, cirrocumulus, and altocumulus. Colors are usually pastel made by a diffraction phenomenon.
Wave Clouds are formed by atmospheric internal waves. It is usually created by a simple convection above the mountain range. This type of cloud is made of supercooled liquid at the lower part with ice crystals on the downwind of the waves.