I remember:
There may be 假冒花梨木eo da bo~
Because to get the eo of 花梨木,it needs to cut off the tree(~some ten-year-old)[Not environmental-friendly ar]
So some bad merchants will use its leaves,or sth like that to 假冒the true花梨木oe~
From the book"The Bloomsburry Encyclopedia of Aromatheraoy"
it stated that 理論上THEOECAN be kept for some years,
except the 柑橘類精油is only for 6-9months.
But some special OE will be better and better when time pass,
just like 陳年,for example,乳香,檀香,廣霍香,