Strange orange disk thing in sand

[SeaMaiden92]

Hi! About a month ago, I found this weird red-ish orange disk in the sand near the glass. It was before I had an account here, so I had no one to ask about it. I took some pictures of it, but it disappeared when the substrate was disturbed. (I'm assuming it was buried) Last night I saw it again. I didn't want to scare my fish by turning on the light so I decided to try getting a picture of it in the morning. Unfortunately it has once again disappeared. I did get a low quality video of it las night though. It is small, I'd say a little less than 1/4 inch wide. It is completely flat, red-ish orange, and see-through. It has little rings on it's flat sides and a little dot in the center. The edges seem clean and smooth. It doesn't seem to move on it's own, unless it's so slow you can't see it moving with the naked eye. Does anyone know what it might be? Ignore the algae on the glass in the pictures, I was fighting an algae outbreak at the time.

 

[Timfish]

My guess is it's a blob of cyano.

 

[homer1475]

Looks to be an opperculumr, or the trap door for a snail.

Loose any turbo snails? Their opperculum is rather large and by your description, just what you have.

 

[SeaMaiden92]

Looks to be an opperculumr, or the trap door for a snail.

Loose any turbo snails? Their opperculum is rather large and by your description, just what you have.

I did lose a turbo snail. That could be it! Thanks!