You will also need to buy a ring that matches the style of the jewelery of your girlfriends collection to get a good idea for what type of ring she will like the best. However if you are stuck and unsure of what ring to get then the blue topaz with 14k gold. In my estimation the pure version of an engagement ring can cost up to 3 times more than the impure version. A good idea would be to sneak into her private area when she is at work a look for any colours of gemstones and type of bodywork that she likes the best. When buying an engagement ring for your girlfriend you need to consider several factors such as the size of the gemstone and the quality of the framework that the ring is made from which is usually gold or silver. There is little visual difference between pure gold and gold that has a small percentage of impurities such as tungsten and cobalt. However the price difference between the two can be huge.

The price of the ring is determined by the size of the gemstone and the purity of the gold or silver in the ring framework.