含有蠕虫状内含物的钙铁榴石 - Diakon，卡伊，马里 - 高度: 3.8 cm - 宽度: 3.6 cm- 46 g

Watch a video of this specimen by following the Vimeo link below:
https://vimeo.com/930295998

I recently got acquainted with what is probably the most comprehensive collection of Kayes region skarn minerals, patiently gathered by a knowledgeable geologist and collector over more than 10 years directly on the field in this remote region of Mali: what a blast I had!
The variety and quality of the Kayes minerals is much wider than I expected, with individual discoveries actually meeting the highest standards for garnet, vesuvianite or prehnite.
In particular, the colour palette and facies diversity for andradite garnet simply ranks the Kayes skarns among the very best localities for the species on Earth.

It is however quite hard and time-consuming to find quality specimens: after reaching Kayes from wherever you would stay, it does take a half day 4x4 truck ride on trails to make it to the villages where local miners and farmers live. Then several days on-site are needed, time for the field collectors from all neighbouring settlements to converge. Unfortunately, the skarn deposits artisanally mined there are thankless: most crystals are strongly oxidized or extracted in a poor condition due to the lack of free space for crystal growth and the mining methods used. Colorful, lustrous crystals are rare and fine garnets are often broken to reveal any gem core that could be valuable for the cut stone market.
Actually, most of the time, a buyer would probably leave without any good rock. Then, repeat this procedure several times a year over a large number of years and you could possibly end up with fine Kayes mineral specimens!

This is why I am thrilled to share with you the result of a careful and short selection among hundreds of collection pieces from Kayes I was lucky to search through.

Here is an absolutely unique garnet crystal (3.5 cm large) featuring never-seen-before convolute worm-shaped inclusions, that make for a stunning visual effect since it contrasts fundamentally with the sharp dodecahedral crystal shape!

After close-up examination under strong magnification, I assume these 'worms' to be reaction halos with a green Cr-rich pyroxene (?) and transparent white stilbite (or another species?). The reaction leading to the formation of such halos is unknown to me and further analysis should be performed on the sample to know more about it.

You have here something truly unique from Kayes, I have not seen any other specimen like this one. The crystal is complete, lustrous, of good clarity and colour. The occurrence of the 'worms' is striking since it smashes the crystal geometry. Everything is complete and recrystallized, you can also notice some white-bluish chalcedony (or opal) crusts on some faces.

An unique, special andradite crystal from Kayes!