A Neelam, or Blue Sapphire, is arguably the most powerful gemstone in Vedic astrology. Beyond its stunning aesthetic, it possesses unique physical and metaphysical features that distinguish it from any other stone. Physical Features Mineral Family: It belongs to the Corundum family, just like Rubies. Extreme Hardness: Neelam is exceptionally durable, scoring a 9 on the Mohs scale. It is the second hardest natural substance on Earth, right after the Diamond. Color Profile: While the primary color is blue, its shades range from light Cornflower Blue to deep Royal Blue. The most prized feature is a "velvety" luster. Specific Gravity: It is a dense stone with a high refractive index, meaning it bends light beautifully, giving it a characteristic "glassy" brilliance when cut correctly.