Calcium is a soft gray alkaline earth metal with symbol Ca. It is found in various salts like calcium chloride, calcium nitrate and calcium carbonate as Ca2+ ion. In group V, calcium ions are precipitated as their carbonates by adding ammonium carbonate to their solution. Calcium ion reacts with ammonium oxalate to form a white precipitate o calcium oxalate and it imparts brick red colour to the flame.
This video explains how to test for the presence of calcium ion in a given salt.