CK Carbonaceous Chondrites are a distinct group of Carbonaceous Chondrite meteorites that have experienced significant thermal metamorphism on their parent body. The ‘CK’ designation comes from the Karoonda meteorite, the type specimen of the group. Formed over 4.5 billion years ago, CK Chondrites began as primitive material similar to other Carbonaceous groups, but were later altered by heat, which modified their minerals and reduced the visibility of original features such as chondrules.

CK Carbonaceous Chondrites are typically dark grey to black and often display a more recrystallised, compact texture compared to other Carbonaceous Chondrites. Chondrules may still be present but are often less distinct due to thermal processing. They generally contain very little metal and are rich in oxidised minerals, reflecting the conditions under which they were altered. Their appearance can sometimes resemble more metamorphosed Ordinary Chondrites, though their chemistry remains distinctly Carbonaceous.

Studying CK Carbonaceous Chondrites provides valuable insight into how heat can alter primitive asteroid material while still preserving its overall chemical signature. They help bridge the gap between unaltered Carbonaceous Chondrites and more processed meteorite types. For collectors, CK Chondrites are relatively uncommon and offer a unique combination of primitive origin and thermal alteration, making them both scientifically interesting and distinctive within Carbonaceous meteorite collections.