These macro and micro photographs depict a gemstone, a variety of jasper called Ocean Jasper, found only in Madagascar. Scientifically speaking its origin hasn’t been investigated extensively, so that the way it acquired its beauty and its peculiar features – starting from a quite ordinary volcanic rock – is far from being known. Ocean Jasper has become a fairly collectible stones for lapidary, as its mines are either out of production, or located below sea level.


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Like other jaspers, the rock is characterized by the presence of spherical aggregates a few mm in diameter (normally 1 to 3) that are called spherulites or “orbs”. These microstructures formed during the alteration of former tuffs or rhyolites, accompanied by extensive deposition of SiO2 (silicification). The micro images in this article are taken under a polarizing transmitted microscope – the interment used by geologists to study rocks – using thin slices of rock (30 micrometers thin). the subjects range in size from 0.5 to 5 mm.

I knew Ocean Jasper is very photogenic, and have long searched for some affordable samples. One night I saw a necklace in a market stall and I bought it. My wife thought it was a present for her, but instead I cut the beads and had thin sections prepared from them. Under the microscope Ocean Jasper is fantastic! It contains a microscopic garden of spherulites of quartz in a fine-grained silica matrix (chalcedony). These spherulites resemble flowers: sunflowers, asters, daisies. In places some coarser crystals form “rosettes” in a lawn of fibrous quartz.

Enjoy!

More info: microckscopica.org

Gorgeous 15 cm in height solid block of Ocean Jasper

Kindly provided by Stefano Avesani

Micro vs. Macro

Macro shot with details of spherulitic “orbs”

Macro shot of the surface of a sample of Ocean Jasper showing the variety of colors and textures of spherulites

Colors of polarization

Polarized light photomicrograph of a thin section of Ocean Jasper showing the details of one spherulite consisting of fibrous microcrystalline quartz (Chalcedony)

Macro shot with details of spherulitic “orbs”

Macro shot of the surface of a sample of Ocean Jasper showing the variety of colors and textures of spherulites

Microscopic geometries

Polarized light photomicrograph of a thin section of Ocean Jasper showing two spherulites consisting of fibrous microcrystalline quartz (Chalcedony)

Macro shot with details of spherulitic “orbs”

Macro shot of the surface of a sample of Ocean Jasper showing the variety of colors and textures of spherulites

The Sunflower! One of my best photomicrographs.

Polarized light photomicrograph of a thin section of Ocean Jasper showing one spherulite consisting of fibrous microcrystalline quartz (Chalcedony)

Kaleidoscopic crystals

Polarized light photomicrograph of a thin section of Ocean Jasper showing two touching spherulites made of fibrous microcrystalline quartz (Chalcedony)

A garden of microcrystalline quartz

One of my favorite images: an aggregate of spherulites recalling flowers in a lawn.

“Rosettes” of quartz in an Ocean Jasper