A liquid embolic composition of natural polymers, water, and angiographic contrast agents improves neurovascular interventions, making them more reliable, safe, and affordable. The embolic material is made of a single component activated by blood calcium ion, which triggers coagulation, and that offers superior mechanical stability and does not cause fragmentation in the target vessel. The material retains superior long-term mechanical durability after deployment and provides sufficient visualization under fluoroscopy with iodine-based angiographic contrast compounds or other radiopaque compositions. Described herein are aqueous solutions that enable a high concentration gellan gum (greater than 0.5 wt%) to retain sol state even at the range of body temperature (30-40 °C). This discovery means that it is possible to increase the concentration of gellan gum without losing its inject-ability, yet significantly improve its mechanical stability after delivery.