I really can't tell from the pic and any pics really need to be taken in natural light to show off the true shine of Diamonds! I will say, if some or all have the appearance of the dull side of Aluminum Foil in person, then it is a good chance that any with this appearance are actual Diamonds. The one thing working against them from being natural White Diamonds, is the fact that there is really only one place in the U.S. that is known for high quality White Diamonds and that is the Crater of Diamonds State Park In Murfreesboro, Arkansas. The Lamproite (Volcanic) Pipe (formerly thought to be a Kimberlite Pipe) there has produced higher quality Diamonds than practically any other location on Earth and in Whites, Yellows, Champagnes and Browns.
Frank