A novel chalcone derivative, (2E)-3-(3, 4 dimethoxy phenyl)-1-(1-hydroxy-2 naphthyl)prop-2-en-1-one (DHNP), C21H18O4, has been synthesized from the mixture of 4-hydroxy acetophenone (0.05mol) and 4-hydroxy-3-ethoxybenzaldehyde (0.05mol) by Claisen-Schmidt reaction mechanism. The structural features of the grown crystal were elucidated by single X-ray diffraction (XRD) studies which confirm the title compound, belongs to the monoclinic system with the P21/n space group. Functional groups, the number of unique proton and carbon environments were identified using FT-IR, 1H, and 13C NMR spectral investigation. The optical behavior of the crystal was analyzed by UV-Vis absorption studies, and the value of the optical band gap energy (𝐸𝑔) of the crystal is found to be 3.386eV. The Photoluminescence (PL) spectrum of the compound indicates the green to yellow light emission in the visible region. By employing thermogravimetric analysis (TGA), the thermal stability of crystal and the dehydration and decomposition nature were found. The Coats and Redfern relation was applied to evaluate the kinetic and thermodynamic parameters. Mechanical properties such as the Hardness (HV), Meyer's index (n), Newtonian resistance pressure (W), load independent constant (b), and elastic stiffness constant (Cij) were calculated by performing a Vickers hardness test on the compound and found to exhibits an excellent mechanical power.