hessonite การใช้

• Some rhodolites will change color from purplish to a hessonite brown when heated to a temperature of 600 癈 . This process cannot be reversed.
• Hessonite comes chiefly from Sri Lanka and India where it is found generally in placer deposits, though its occurrence in its native matrix is not unknown.
• The different species are pyrope, almandine, spessartine, grossular ( varieties of which are hessonite or cinnamon-stone and tsavorite ), uvarovite and andradite.
• It was shown many years ago, by Sir Arthur Herbert Church, that many gemstones, especially engraved gems ( commonly regarded as zircon ), were actually hessonite.
• The difference is readily detected by the specific gravity, that of hessonite being 3.64 to 3.69, while that of zircon is about 4.6.
• Hessonite has a similar hardness to that of quartz ( being about 7 on the mohs scale ), while the hardness of most garnet species is nearer 7.5.