The authentic Belgian blue stone is a compact crinoid limestone, sedimentary in origin. Its non-porosity and density make it more resistant than other, imported stones of similar appearance. The oolites in Asian dolomitic stone, for example, oxidize with time and create unsightly rings.
Foreign stones or imitation blue stone do not have neither the same sparkle nor the properties of blue limestone. Unlike them, the unpolished Belgian blue stone takes on a beautiful patina with age.
To learn more about the qualities of Blue Limestone of Hainaut