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A ruby is measures a 9 on the Mohs Scale of Hardness, second only to diamond and matched with sapphire. This makes a ruby an extremely hard and durable gemstone.
A sapphire is the birthstone for September. It is also a traditional gift for those celebrating 5th or 45th anniversaries.
there are 28 neutrons present
<span>Kepler found that the orbits of the planets were elliptical.
His work was so convincing that to this day, they still are. </span>
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sorry I don't know I am too bad a t this coz I am only at class 7