I do see a lot of people doing SG’s the hard way using all sorts of jigs and contraptions to try and measure the weight of the stone in water. There’s a simpler way – you just need to measure the weight of the water displaced by the stone when fully immersed.
You will only need an accurate carat scale (accuracy to at least .01g), a small beaker/glass of water, a calculator and some fine cotton.
Divide 2.06 by 0.76
That’s it; done.
Walter Schumann Gemstones of the World says for aqua SG: 2.68 – 2.74
Bang in the middle!