YELLOW SAPPHIRE

Yellow sapphire is also known as Oriental Topaz. It is basically Corundum and comes in many other colours as well. The chemical composition is Aluminium Oxide with a formula of Al2O3. The yellow sapphire is mainly found in Queensland and New south Wales in Australia. Even Sri Lanka,East Africa also produce this type of sapphire. The sapphire has hardness of 9 ,specific gravity 4.00,refractive index 1.76-1.77 with a Trigonal crystal structure.
This stone drastically helps in memory and learning. It is also an effective stone to decrease the effects of snakebite. It helps balancing stomach, gall bladder, spleen, and liver.
Yellow sapphire is the precious stone for Jupiter. The semi precious substitute is Golden Topaz.
Golden Topaz is actually golden yellow in colour and is sometimes called as Sherry topaz also. Although topaz occurs in other colours also, but golden yellow is in the category of gems. It is basically Aluminium Fluorohydroxysilicate with a formula of Al2(F,OH)2SiO4. It is found in igneous rocks and sometimes in alluvial deposits as pebbles also. It is found in USA,Sri Lanka,Burma,former USSR,Australia,Pakistan,Mexico,Japan and Africa.
Topaz has hardness of 8,specific gravity 3.54,refractive index 1.62-1.63 with a crystal structure of Orthorhombic.