CINNAMON-STONE, a variety of garnet belonging to the lime-alumina type, known also as essonite or hessonite, from the Gr., "inferior," in allusion to its being less hard and less dense than most other garnet. It has a characteristic red colour, inclining to orange, much like that of hyacinth or jacinth. Indeed it was shown many years ago, by Sir A.H. Church, that many gems, especially engraved stones, commonly regarded as hyacinth, were really cinnamon-stone. The difference is readily detected by the specific gravity, that of hessonite being 3.64 to 3.69, whilst that of hyacinth (zircon) is about 4.6. Hessonite is rather a soft stone, its hardness being about that of quartz or 7, whilst the hardness of most garnetreaches 7.5. Cinnamon-stone comes chiefly from Ceylon, where it is found generally as pebbles, though its occurrence in its native matrix is not unknown.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)