It has been long established that the right balance in trace elements is required to ensure animal health and optimal growth. Hair is particularly rich in trace elements such as sulfur and it has been proposed that the quality of fibres derived from hair may be influenced by the amount of trace elements present. In this study, we evaluated the quality and mineral content of Raeini goat cashmere over the course of 1 year. Potential factors that can influence the mineral content of cashmere were further considered, including sex, age, seasons, herd variables and serum trace elements. Twenty-four male and 48 female Raeini goats were selected and a total of 216 fibre samples were taken during two 6-month intervals of annual fibre growth from nomadic, rural and breeding station flocks. In addition, samples of blood, soil, range forage, animal ration (hand feeding), and surface and deep water from four seasons were also obtained. The results indicate a positive correlation between cashmere percentage and zinc content. In addition, we also observed a negative correlation between cashmere tenacity and its zinc, sulfur and serum copper content. These results provide new insights into the factors affecting cashmere quality, and will aid in designing new studies for determining the best combination of factors that lead to optimal cashmere quality.