Trying to find a 60s Sci Fi. HELP!

[#Moist]

When I was around 8, I remember watching an old Sci Fi film from around the 60s. I don't remember much of it but I do remember one part were a space man finds a stone with a jewel sticking out of it. At the end of the film, he breaks away a layer of stone and finds that it is a carving of a beautiful woman's face and the jewel was one of her eyes. I've been searching for this film for ages and couldn't find a thing. Please please please help!
Thanks

A couple more things I remember: I think the stone was found underwater and I'm fairly sure that the film was a double feature (possibly with Unknown World, The Phantom Planet or First Spaceship on Venus)

 

[Foxbat]

Your description sounds like a movie that might include somebody like Doug McClure but I don't think it's one of his and I'm pretty sure it's not Unknown World.

American International Pictures originally released The Phantom Planet as a double feature with Assignment Outer Space. First Spaceship on Venus was doubled with Varan The Unbelievable for American release. I don't think any of these movies are the one you seek. Sorry.

 

[J Riff]

Got to be Voyage to the Prehistoric Planet , or: Voyage to the Planet of Prehistoric Women. These flicks share footage.
Will be posting a review soon.

 

[Victoria Silverwolf]

Definitely correct. Both with footage taken from the Soviet film Planeta Bur.

Voyage to the Prehistoric Planet is closer to the original.

Voyage to the Planet of Prehistoric Women is a lot goofier.

The scene you mention is from the Soviet original, and is quite striking.