Matrix. Calcifications or mineralization within a bone lesion may be an important clue in the differential diagnosis. There are two kinds of mineralization: a chondroid matrix in cartilaginous tumors like enchondromas and chondrosarcomsa and an osteoid matrix in osseus tumors like osteoid osteomas and osteosarcomas.
Oil refinery jobs will have one set of required qualifications, while other jobs may have different qualification requirements. You will need to complete a high school education in order to become a refinery operator in most cases. Once you finish high school, it is a wise decision to enroll in an associate's degree program that will train you for work as a refinery operator.
Blue-collar workers perform labor jobs and typically work with their hands. The skills necessary for blue-collar work vary by occupation. Some blue-collar occupations require highly skilled personnel who are formally trained and certified.