Advantages of lightening dark Ebay Auction Photos

Recently I bid on and won these pink agate beads on Ebay.

I was uncertain as to the exact color of the beads, so downloaded the photo, lightened it up and here is what they should look like when they arrive:

If a person had bid on and won these beads, they would've expected a darker hue of pink, and may have been dissapointed upon their arrival.

An Ebay seller is running an auction for these beads they call "Multicolor Jade" beads.
These are also called Kunzite beads.

Here is an Ebay auction photo of faceted gemstone beads they call "abacus" beads.
Another name for them is "rondelle" beads. 
The seller calls this gemstone "pink red ruby".

This is a "multicolor ruby" necklace made of faceted beads being auctioned on Ebay.

Here I sharpened and lightened the photo to reveal the color and faceting of the beads.

An Ebay seller calls this  a "light green opal" bead necklace.

After sharpening and lightening the photo, here is what the beads will really look like.
Some sellers call this gemstone aquamarine, others call it apatite.
Whatever it is called, its a beautiful stone.
It doesn't look like opal to me.

These are what some sellers call "Swarovski crystal AB" beads.
They are not real Swarovski crystal, but Swarovski crystal STYLE beads.
The are partially plated with silver metallic coating.
They are not crystal, but are faceted glass.
AB indicates they have some "flash" to them (the metallic hues give off glittery light when light reflects on them).

Now these are very fine "Swarovski" beads the same seller is selling.
Note how gorgeous the hues of blue plating are on these beads.

Here are what some sellers call "frost agate" beads.  They come in all different types of colors.  Some call them "cracked" or "crackled".

The same seller is selling these beads and calling them "Dream Fire agate" or "Dragon Vein agate".