This was taken from another thread directly from Bungie Help.
[quote]Hello all.
This shader should become available after collecting all 50/50 Calcified fragments.
If you have done this and still do not have access to the shader within your Collection, please let me know in the form of a reply to this thread.
Please provide a screenshot showing that you have 50/50 Fragments (This can be seen in the Director when viewing the Dreadnaught), as well as a screenshot of your collection showing the Beltane Shader unavailable.
Thank you for your patience.[/quote]