Trying to identify this playing card reveal I used to have and my memory may be playing tricks on me but the card or part is revealed by looking at a crystal .
Its not the one where its etched in and moisture helps the reveal . I think it was at the end of a glass tube .... does anyone remember this effect ?
It may be as simple as an index held against a tube but I struggling to remember the trick

Mike Rogers had a similar sounding effect utilizing a small clear "crystal ball".

Julie

In the old D.Robbins/E-Z Magic catalogs was an item called Telescopic Card.

This set was comprised of two small plastic telescopes (tiny, like for children's party favors). One had the index matching a force card added to the inside of the lense.

The routine was to have the non-gimmicked telescope examined by your spectator. You would force the card that matched the index hidden in the second telescope. Of course, somewhere in between all this activity you would switch the ungimmicked telescope for the second gimmicked telescope with the matching index inside.

All that remained was for the original spectator or a completely different spectator to look into the telescope and name the selected card.

Not a bad trick and I have seen suitable telescopes in the party favors section of the dollar stores.

Hope this answers your question.

Julie

In Annemanns Practicle Mental Effects, there is a card reveal using a crystal ball.
I also remember a trick that used a clear marble as a crystal ball and the image of the card would appear in it.

There was (is?) a similar version to the above employing a square clear Cube(s) the relative size of a gaming die.

Julie

Richard Osterlind has a crystal ball reveal routine in Eerie

The original effect was called 'The Eye of Cyclops - created by Louis Histed (of Square Circle production box fame), and first released by The Unique Magic Studio (Harry Stanley, London) in 1951:

https://www.martinsmagic.com/allmagic/cl......-histed/

As is usual with any good idea in Magic, it's been ripped-off ever since.