GUEST: My father's turning 92 this year.

He has had this vase since he was a kid, and the story he tells is that his aunt came to this country from Ireland and got a job as a housekeeper in one of the North Shore, Long Island, estates.

And she brought it home from the estate.

We assume it was a gift.

And that's back in the early 1900s.

We know it says "Tiffany" on the bottom, and it's been in a closet for 40 years.

You go online, you see a lot of fake Tiffany.

We found a lot of vases that look liked it, like it, but they're not Tiffany, so we're not sure.

APPRAISER: I'm glad you brought the vase in, because it is indeed a... GUEST: Oh, thank God.

(both laugh) APPRAISER: It's a Tiffany paperweight glass vase.

GUEST: Okay.

APPRAISER: But not only is it a Tiffany paperweight glass vase, but it's actually a reactive paperweight glass vase.

So, it's a little more of a complicated technique involved to make it appear this way.

This was a technique that was developed around 1910, 1911.

Really.

The color can be different, whether it has transmitted light or reflected light on the piece.

GUEST: Okay.

APPRAISER: But if we look at it-- and today, we're looking at it more with, uh, reflected light-- it looks one way.

GUEST: Right.

APPRAISER: If we took that light away, the colors would completely change.

GUEST: Really?

APPRAISER: The paperweights themselves were first developed, and it was, like, a very major innovation at Tiffany glassworks.

They started to make paperweight glass just around 1900.

This would have been made in Corona, Queens.

The technique was the same type that you would use on making an actual paperweight, in that you would have hot cased glass, and then you'd put a transparent layer of glass on top.

And as a result of that, the decoration that's trapped in between it... GUEST: Right.

APPRAISER: ...so it has a much more three-dimensional effect.

This is leaves and vines, and you can see traces of some type of flower.

I love the blue, is gorgeous.

(murmurs) And the swirling effect in the background.

There are a few imperfections.

GUEST: Right, yeah.

APPRAISER: There are some blisters, and then on one side, there is a blister, and we call it, like, a, a burst bubble.

GUEST: Oh, that's from manufacturing, is it?

APPRAISER: Yes.

GUEST: Okay.

APPRAISER: Now, that will affect the value.

APPRAISER: Never, nevertheless, I would put a retail value of $10,000 to $15,000.

GUEST: Really?

Okay-- wow, very nice.

Yeah, that's... Take it out of the closet?

(laughs) APPRAISER: For insurance, maybe $20,000.

GUEST: Okay.