Pranaya:

We cannot be sure about the Diatom nature of these spherical objects, till you furnish better pictures and mineral composition.

Best

Syed

I agree with Syed Sir. You need to post clear pictures for identification.

Ok sir i will try for better image 

Dear Pranaya,

agree with all the above comments but i would like to make a  guess based on what i could make out from your image and my suggestion is that it could be a species of acentric diatom like  Asteromphalus  or Thalassiosira .

Good luck!

Pranaya sir,

                        I am also of the opinion that it could be Asteromphalus (Jackson sir's comment) with the image provided by you. Since it lacks a good exposure the area in the centre shows a vague astral structure, hence the answer. A better exposure to the image in terms of light source would enable you to confirm it. In fact do post it if you manage to get a good image. will be interesting to see and know if it really is the diatom we named.

All the best..

Dear Pranaya:

As Syed and Arvind I think that your material is not a diatom.

Genus Asteromphalus is marine planktonic and Genus Thalassiosira is dominantly marine and planktonic, both are morphologically very different that your material.

You can consult for seeing one examples of each one, in these links:

https://www.google.com.ar/search?q=asteromphalus&source=lnms&tbm=isch&sa=X&ved=0ahUKEwi6tfzy_8_PAhVCDZAKHVDrBcgQ_AUICCgB&biw=1138&bih=543#imgrc=T-OM5D4cNwrLEM%3A

https://www.google.com.ar/search?q=thalassiosira&source=lnms&tbm=isch&sa=X&ved=0ahUKEwi63qqxgdDPAhXDCpAKHcHLBpgQ_AUICCgB&biw=1138&bih=543#imgrc=6ZS-j1k4n5CQsM%3A

Kind regards.

Eugenia

Please find the new picture herewith attachment.