Glass returns 4% of light at normal incidence in air but less than 1% when in water. Diamonds, (refractive index 2.42) retain most of their sparkle under water (advert at left).
Details
High angles of incidence - dark water - Lake Matheson NZ.
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Glass returns 4%
of light at normal incidence in air but less than 1% when in
water. Diamonds, (refractive index 2.42) retain most of their
sparkle under water (advert at left).