670-61-16-63 cmd@cristalljoia.com In the heart of Barcelona and online
Shopping Cart
Bismuth, the laboratory-grown crystal
Discover the geometric bismuth made with heat, time and pure physics.
Read more
Moldavite: not a meteorite, not a mineral. What is it really?
Not a meteorite, not a mineral: discover what moldavite really is and why none has formed in 15 million years.
Read more
Violet, green, red, blue... what determines a mineral's colour?
Why amethyst is violet and opal shimmers: the colour of minerals, explained.
Read more
Shape tells the story: how to read a mineral by its crystal habit
Learn to read a mineral by its outer shape: what crystal habit tells you about how, where and how fast each stone formed.
Read more
Tourmaline comes in far more than just black
Pink, green, blue, black, watermelon... each color is the result of a different chemical composition. The same mineral, endless possibilities.
Read more
Emerald, sapphire, ruby. Raw and cut. Same stones, two prices.
An emerald can cost €3 or €30,000. It's the same mineral: what changes is whether the crystal is transparent or not.
Read more
What determines the value of a mineral?
The value of a mineral isn't in its name. It's in how it formed, and in how unlikely it is that nature created exactly that piece.
Read more
Uruguayan amethyst: small points and deep violet. Brazilian: large and lighter. Why?
Why does natural amethyst from Uruguay have small points and such a deep violet, while natural amethyst from Brazil has large crystals and a lighter colour? We explain it all here.
Read more
Is obsidian a mineral? The answer might surprise you
Obsidian is one of nature's most fascinating stones… and it turns out it's technically not a mineral. Find out what it really is, why, and the curiosities that make it truly unique.
Read more