Welcoming the New Year with a bang is a common tradition followed by almost every country. Some like to dance, some party while there are many who just sit calmly and welcome the New Year while praying to god. The basic gesture that is promi...英国华人论坛
Fireworks can be the most dangerous explosives and are best handled by trained professionals.It is hard to imagine the Fourth of July without fireworks. More people ignite simple or homemade fireworks each year than attend large-scale firewo...英国华人论坛
Fireworks were invented in China in 7th century AD. The knowledge of Chinese firework invention spread wide and far with adventurers traveling around the world. In the middle of the 13th Century, it was Marco Polo who brought the science of...英国华人论坛
It is hoped that by reading the information contained within, you will have a better understanding of where opal comes from, how it is mined, and the value and various types of opal available to the collector, investor, or those who just wan...英国华人论坛
Following is a synopsis of the countries where opal is currently mined:Mexico:The Mexican opal fields are primarily located in the Queretare and Jalica regions. These regions have been known to be producing opal since the time of the Aztecs,...英国华人论坛
Although in reality all that is needed to get started mining opal is a pick, most miners now consider a jackhammer and an electric hoist a machine used to get opal-bearing dirt to the surface the minimum equipment needed. Most shafts a...英国华人论坛
During the Cretaceous period (65-140 million years ago) deserts were an inland sea teeming with life. The sea gradually receded laying the foundation of silica that would form the opal of today. During the mid-tertiary period, changes in the...英国华人论坛
Valuing OpalsWhen determining the value of an opal, several factors are involved:Type of opalSoundnessBase colourFire colourColour patternBrightness of fireBackground (base) Colour:Solid precious opal is more valuable than a doublet or tripl...英国华人论坛