©
finnchaga: Refractive index reading of an Epidote Crystal
©
finnchaga: Another tool for investigating minerals
©
finnchaga: Reflectometric measurements of ore minerals
©
finnchaga: A set of Classic Gemmological Tools
©
finnchaga: Natrium-lamppu gemmologiaa varten - Sodium lamp spectrum
©
finnchaga: New tests with laser-filtered fiber-optic light
©
finnchaga: There are filters and then there are filters