Jewellery Box made from Alabaster???

I was going through some boxes and found this gem. Its 3 X 3 X 1.5 inches and weighs 15.665 oz's. It so nicely made, no chips, cracks with the one natural imperfection shown in the corner. The darker blue colour. I have researched alabaster but there is no blue coloured alabaster unless all you "rock hounds" out there can tell me different. There is a light milky blue one, but this is quite navy coloured.
Can anyone help me? Thank you..blingiton1948