Identifying a Black Crystal Opal

There are many categories of opal when it comes to grading them out.Opals of all different colors are and have different values depending on the color it displays.You can categorize opals by using ...

What type of opal cutting machines can I use?There are many cutting machines and ways to cut and polish opal. Finding the opal-cutting machine to suit you is the question that most people have on t...