At that time, this collection consisted mainly of minerals, fossils, partly of mussels, snails, crustaceans and a few botanical objects. Unfortunately, Saint Laurent's description gives no concrete evidence of certain minerals in this collection and even the first catalogue of the Viennese Mineral Collection, the "Catalogus Stützianus", written by Andreas Stütz in the years 1797-1806, only shows very rare indications of these, so that nowadays we only know for certain that a few of the beautiful Colombian emeralds were already part of the former private collection of Johann von Baillou, among others the samples which Franz Stephan of Lorraine, surrounded by the directors of his collections, is shown holding in the painting by Jakob Kohl und Franz Meßmer on the interior staircase leading up the Museum of Natural History.
Unfortunately, most of the several thousand samples, which the Emperor must have obtained as part of the Baillou Collection, can no longer be identified because of gaps in the records and to the minerals and fossils, as well as precious and decorative stones acquired by the Imperial Household during the years 1748 and 1797. The same applies to the description of the collection itself, of the comprehensive historical work carried out between the years 1748 and 1802. There is a contradiction in the reports on the "Alte Naturaliensammlung" (Old Natural History Collection), the "Hof-Naturalien-Cabinet" (Court Natural History Cabinet) and the "Kaiserliche Naturalienkammer" (Imperial Natural History Chamber) etc. (i. e. FITZINGER, 1856; BLÖCHINGER vom BANNHOLZ, 1868; HAMANN, 1976).
However, the Emperor was not content to let the purchase of the "Baillou" Collection end his activities. He is reputed to have made a considerable sum of money available, being prepared to have an open mind to problems in natural science. A famous example, possibly apogryphical, is the experiment which Franz Stephan carried out in the co-operation with the Jesuit priest Joseph Franz (1704-1776), known for his work in physics, to verify the combustibility of diamonds. He also initiated a series of expeditions that were to supply new material for his collections. For example, Nikolaus von Jacquin and the Imperial gardener Richard van der Schott travelled first to France, from where they shipped minerals among others (FITZINGER, 1856), then to embark on the voyage to Central America. About 50 boxes were brought by Jacquin with species from nature and artefacts to Vienna. Presumably the platinum samples from Choco in Columbia, which are already included in the "Catalogus Stützianus", were part of this shipment. Johann von Baillou dies in 1758 and his son Ludwig Balthasar von Baillou assumes the management of the collection in accordance with the earlier agreement.
Maria Theresia, co-regent in the Habsburg dominions, shared her husband's interest in the sciences. She presented Franz Stephan with the wonderful bouquet of precious stones, which is justifiably considered as the founding object of the precious stone collection of the Viennese Museum. 761 variegated stones and 2,102 diamonds were used in the assembly of this bouquet of jewels - representing a bouquet of flowers, along with diverse artistically reproduced insects, leaves of silk, contained in a vase of rock crystal. Maria Theresia is said to have put this bouquet in the Emperor's Mineral Cabinet one spring morning (FITZINGER, 1856). Traditionally, it is alleged that this is Viennese work; it is ascribed to a Viennese jeweller, Michael von Grosser. However, there is some evidence that the bouquet originates from Georg Gottfried Lautensack, a jeweller from Frankfurt and that Goethe in his youth was already intrigued by the manufacture of this objet d'art (NIEDERMAYR, 1989). Taking historical developments into account, which are dealt with in Goethe's fourth book: "Aus meinem Leben" (From my life), the bouquet must have been almost completed by the year 1763. The Emperor's son, later to be Emperor Joseph II, was crowned King of the Germans in Frankfurt in the year 1765 and died in the summer of the same year.
Maria Theresia continued in the tradition of the Viennese "Naturaliensammlung" (Natural History Collection), but in her personal practical way of thinking, with the consent of her son, then Emperor Joseph II, she assigned all of the Imperial Collections to the supervision of the Oberstkämmerer.