Haghia Triada roundels & noduli:

Linear A nodulae with syllabogram SI from Haghia Triada

From: The Haghia Triada administrative documents:

http://www.aegean-museum.it/musint2/en/crete/documents.inc.php

Descriptions from this site (quoted):

Although the writing has not been deciphered neither the language has been interpreted (sic, poor grammar) various data may be obtained from the tablets. First of all, a list of Linear A signs may be hypothesized, which, with its 97 symbols, reveals a syllabic script of a simple typology (consonant + vowel and vowels): the signs are, in fact, too many, to represent a complex syllabic system (as the Near Eastern Cuneiform and the Aegyptian Hieroglyph). To these syllabic signs a long series of "logograms", representing each one a word, are added. 

Types of seals represented:

nodulae and roundels from Haghia Triada

Roundels:

The roundel is a characteristic document of the Neopalatian Minoan [1] administration, beside the tablet. It is a round clay disk (classified as Wc) with seals impressions along the edge - from one to six impressions - and, on most cases, one inscription on one or both sides. Frequently the inscription consists of a logogram, sometimes also of a sign-group. It seems to represent the last act [2] of an administrative transaction and probably functioned as a receipt. 

The seals stamped on roundels fully coincide with seals stamped on the other different documents. At Haghia Triada 22 roundels have been found, one of them being without (an) inscription. 

Nodules:

It is (sic, They are) the most widespread Aegean Bronze Age document, both geographically and chronologically. These clay small object (sic, objects) (defined as noduli by J. Weingarten) were not always inscribed but only sealed. They appear in two shapes: dome (classified as We) (fig. 4) and disk (classified as Wf) (fig. 5).  At Haghia Triada 54 noduli have been found, in dome shape, and only 7 are inscribed. 

Types:
1 Flat-based nodule:
This type of document is rarely inscribed but regularly sealed. Its characteristic is the negative impression on its reverse (or base) which shows that it had been placed upon a folded piece of parchment around which a thin thread was wound which was also wound into the clay. It appears in two different shapes: standing (fig. 6) or recumbent (fig. 7) (both classified as Wb). At Haghia Triada 76 flat-based nodules have been found, only 2 having a carved inscription. 

2 Hanging nodule [3]:

This small clay piece is characterized by string holes which show that it was fastened to another object by a string. They may present one or two holes. 
Those with two holes (classified as Wd) have an elongated shape (fig. 8), while those with one hole (classified as WA) present five slightly different shapes: pendant, pyramid, cone, dome, pear (fig. 9) [4]. At Haghia Triada 936 single-holes have been found, 851 being inscribed, and 11 two-hole, only 2 being inscribed. 

Comments by Richard Vallance:

[1] Neo-palatial Minoan administration: This is the Minoan administration at Haghia Triada dating from the Middle Minoan MM ca. 1750-1550 BCE & Late Minoan LM1A, ca. 1550-1500 BCE. Documents in Linear A inscribed during the LM1A period may have been inscribed in Mycenaean-derived New Minoan.  
[2] “the last act”. This is ambiguous English. Does it refer to the “the most recent” of the Haghia Triada administration? And if so, does this mean the act or acts date from the Late Minoan LM1A period?  And if so, are these acts inscribed in Mycenaean-derived New Minoan?
[3] The nodules illustrated in my decipherment of Figure 9 above are hanging nodules.
[4] See my 3 decipherments in Figure 9 at the outset of this post. If the syllabogram SI is the first syllable of a Mycenaean-derived New Minoan word, it could represent any of the 3 decipherments I have proposed. If on the other hand, SI represents any Old Minoan word, it is indecipherable.  

Haghia Triada pianta genrale