Both are varieties of Chalcedony.
Chalcedony mineral hardness -> 7 Mohs (Same as Quartz)
Quartz is a mineral composed of silicon & oxygen (SiO2).
Differnece is come from impurity amount. Agate has less, so it's translucent to semitransparent & jasper has more, so it is opaque.
If difficult to differentiate “Jaspagate” term is used when a specimen contains both jasper & agate.
Chalcedony is a composed of micro-crystalline quartz ( Micro means tiny, not seen with eyes ) / cryptocrystalline means that the quartz is in the form of crystals that are smaller than 30 microns in size (a micron is a unit of measure that is 1/1000th of a millimeter).
(Other microcrystalline quartz are bloodstone, carnelian & chrysoprase)
Macro-crystalline ( Macro means large, can be seen by the eye or a simple len) quartz refers to quartz with a crystalline structure.
These include clear quartz, smokey quartz, amethyst, rose quartz, citrine & ametrine, all of which are translucent or transparent.
Diaphaneity means “how easily light passes through a material”
Levels of diaphaneity
- Transparent (light & images pass through)
- Semi Transparent (images may appear distorted or foggy through the mineral)
- Translucent (light passes through)
- Opaque (no light passes through)