try putting it in the freezer for a while and then try it. It worked with a brand new bottle of expensive perfume with a crystal stopper.It may work,can't hurt!
If you get it open you are good to go!

Or. Set the bottle in hot water up to its neck. The lower portion expands enough to loosen.

Hmmm........not sure if the hot water method would work since the material would expand in all directions, not just outward.

The stopper is probably stuck because of the sugar in the Vodka. Try running hot water over the stopper to loosen it. If that doesn't work, try spraying some vegetable oil spray around the lip. Or, try those steps in reverse order. May be safer than using the hot water on the crystal.

Not sure how it will affect the vodka, but put a couple drops of olive oil around the stopper and let it sit for a few hours. Just read this in a book tonight and remembered your post! Hope it works.

Posted by annz: Hmmm.not sure if the hot water method would work since the material would expand in all directions, not just outward.

It works. Thermal heat expansion is a physical science. It may not work in this case because we don't know all the contingencies though.

BTW, vodka contains NO SUGAR. Vodka a is distiled product. There are infused vodkas, that of course, do not contain sugar either. But there are vodka based cordials and liqueurs that have herbs and sugar added after manufacture. If it is a cordial the alcohol around the rim evaporated the sugar may have stuck the stopper. Dissolve it with real vodka.

You can also try holding it by the stopper and gently tapping it with a butter knife or something similar. It may dislodge that way.

Or try a combo of the above methods.

See link below:

Here is a link that might be useful: Unstop the Stopper

Thank you all for your suggestions. What finally worked was the oil for 24 hours or so, then HOT water run over the neck, held sideways, for several minutes,then I coaxed the stopper out. No harm done :-)

I'm glad you got the stopper out, but you really shouldn't store anything in lead crystal. The lead will leach out over time.

It's DH's vodka martini vodka - doesn't last that long LOL.

Happilady is correct. There is a hundred times more lead that will leach out of lead crystal with alcohol than with water in leaded glass. Storing it in a leaded container is more dangerous than the lead you would ingest from drinking from a leaded crystal beverage glass. I would not do it.

Here is a link that might be useful: Lead Crystal Danger