Onyx and semi-precious stones
In the south area of the territory of Montaione, in particular in the area near Iano, there are veins of travertine and calcareous alabaster, that for its structure and colours – usually in tones of grey and white, or brown – is commonly defined inAlabaster-Onyx.
Alabaster-Onyx is a kind of chalcedony with typical white and black veins. In the Montaione’s one, is a simple calcium carbonate exposed to crystallization and precipitation process, filling the vertical cracks of the travertine.
It’s important not to confuse the Alabaster-Onyx of Montaione with the chalky one of Volterra, commonly called Alabastro, which is less precious.
Excavation of Onyx in Montaione, started in locality “California”, the firsts years of the XX century, but it was made intensively in the 70’s when there were 15 operators only in the mining process. In the same time it was diffused the production of ornamentals objects.
In the territory of Montaione, the mining process for onyx employed in 15 operators in 1951, 71 in 1971 and 21 in 1981 with an increase in the first period of twenty years higher than the average of the Valdelsa area. Later, the crisis of the trade in Onyx, caused by the high costs of mining process, reduced the number of operators.
The mining process was extended till the first half of 80’s and today in Montaione there is only one artisan specialized in manufacturing of onyx and semi-precious stones like Agata and Malachite, producing decorative objects.