It is the outcome of True Adamantium’s reinforcement. Wolverine went through the process and survived the deadly process due to his healing factor. However, Adamantium Beta works like True Adamantium but it is not suitable biologically with bones. And that’s why Magento was able to draw out the Adamantium from Wolverine’s body.
Adamantium’s history differs from Earth-616. This time the alloy was partially composed of a meteorite landed in Africa and so the Adamantium was created through an unknown process.
Carbonadium is an unstable and a cheaper form of Adamantium. As per its metallic properties, it is less durable than True Adamantium, however, it is nearly shatterproof. One of the adversaries of X-Men, Omega Red has coils made from Carbonadium.