One of the outstanding Italian mineralogists of the second half of the 19th century, D'Achiardi took a degree in Natural Science in Pisa, his native city, in 1859. Subsequent to a severe laboratory accident which cost him the loss of his left eye, he decided to abandon his studies in chemistry and devote himself to geology and mineralogy. Becoming a pupil of Professor Giuseppe Meneghini (1811-1889), the famous geologist and palaeontologist, he focussed on mineralogical analysis, and was appointed temporary lecturer in mineralogy at the University of Pisa in 1874. In the forefront in the field of petrographic studies thanks to the utilisation of innovative instruments such as the polarising microscope, he also studied problems of genesis and theoretical mineralogy. Highly important among his writings, in addition to numerous scientific memorandums published from 1866 to the year of his death, which took place in Pisa in 1902, are the treatises Mineralogia in Toscana [Mineralogy in Tuscany] (1872), I metalli, loro minerali e miniere [The metals, their minerals and mines] (1883), Guida al corso di litologia [Guide to a course in lithology] (1888) and Guida al corso di mineralogia [Guide to a course in mineralogy] (1900), the first volume of a series completed posthumously by his son Giovanni.