We begin with the following:

Shemoth (Exodus) 24:9-10
Then went up Mosheh, and Aharon, Nadav, and Aviyhu, and seventy of the elders of Yashar’el: 10 And they saw את eth the Elohai of Yashar’el: and there was under his feet as it were a paved work of a sapphire stone, and as it were the body of heaven in his clearness.

The word here that is translated as sapphire is incorrectly set forth by Strong’s as cappiyr (סַפִּיר) Strong's H5601.  There is no double “p” in the word.  Rather, it should be pronounced caphiyr (sapphire). Either way its meaning is determined to be a gem (perhaps used for scratching other substances), probably the sapphire. Probably?

However, the word has a root in the Ivriyt, which is (סָפַר) (H5608).  Now, the Masorites tell us that the pronunciation is çâphar, yet the non-nikkud spelling is identical with H5608-5613.

5608 means: to score with a mark as a tally or record, i.e. (by implication) to inscribe, and also to enumerate; intensively, to recount, i.e. celebrate:—commune, (ac-) count; declare, to number, penknife, to reckon, scribe, shew forth, speak, talk, tell (out), writer.

5609 means: book, or scroll (Aramaic).

5610 means: a census, or numbering.

5611 means: a place in Arabia.

5612 means: from H5608; a writing (the art or a document); by implication, a book: a bill, a book, evidence, a letter, a register, a scroll. It is found also in the feminine form as çiphrâh (סִפְרָה) (Ps 56:8 (H9). The Masculine plural is cepheriym (ספרים); the Feminine plural is cepher’oth (ספרות).

5613 means: a scribe (Aramaic).

When we look at the word sapphire in its totality, we then see in the meaning of the word a fixed stone which may include an enumerated writing scratched upon its surface.

Let’s look at the history:

Shemoth (Exodus) 19:19
And when the voice of the shofar sounded long, and waxed louder and louder, Mosheh spoke, and Elohiym answered him by a voice.

What did they actually hear being said:

Shemoth (Exodus) 20:1-17
AND Elohiym spoke את eth all these words, saying, 2 I am Yahuah Elohayka, which have brought you out of the land of Mitsrayim, out of the house of bondage.
     3 You shall have no other elohiym before me.
     4 You shall not make unto you any graven image, or any likeness of anything that is in the heavens above, or that is in the earth beneath, or that is in the water under the earth: 5 You shall not bow down yourself to them, nor serve them: for I Yahuah Elohayka am a jealous El, visiting the iniquity of the fathers upon the children unto the third and fourth generation of them that hate me; 6 And showing mercy unto thousands of them that love me, and guard my commandments.
     7 You shall not take את eth-the name of Yahuah Elohayka in vain; for Yahuah will not hold him guiltless את eth that takes את eth-his name in vain.
     8 Remember את eth-the day of the Shabbath, to keep it holy. 9 Six days shall you labour, and do all your work: 10 But the seventh day is the Shabbath of Yahuah Elohayka: in it you shall not do any work, you, nor your son, nor your daughter, your manservant, nor your maidservant, nor your cattle, nor your stranger that is within your gates: 11 For in six days Yahuah made את eth-the heavens and את eth-the earth, את eth the sea, and את eth-all that in them is, and rested the seventh day: wherefore Yahuah blessed את eth-the day of Shabbath, and hallowed it.
     12 Honour את eth-your father and את eth-your mother: that your days may be long upon the land which Yahuah Elohayka gives you.
     13 You shall not kill.
     14 You shall not break wedlock.
     15 You shall not steal.
     16 You shall not bear false witness against your neighbour.
     17 You shall not lust after your neighbour's house, you shall not lust after your neighbour's woman, nor his manservant, nor his maidservant, nor his ox, nor his ass, nor anything that is your neighbour's.

Shemoth (Exodus) 24:12
And Yahuah said unto Mosheh, Come up to me into the Mount, and be there: and I will give you את eth-sapphire stones, and a Torah, and commandments which I have written; that you may teach them.

Shemoth (Exodus) 34:28
And he was there with Yahuah forty days and forty nights; he did neither eat bread, nor drink water. And he wrote upon the sapphires את eth the words of the covenant, the Ten Devariym.

Devariym (Deuteronomy) 5:22
את eth-These words Yahuah spoke unto all your assembly in the Mount out of the midst of the fire, of the cloud, and of the thick darkness, with a great voice: and he added no more. And he wrote them on two sapphire stones, and delivered them unto me.

In this record, we see that an enumerated writing – Ten Devariym – were set forth on stones.

In Devariym 5:22, we are told by Strong’s that two words can be found in the underlying Masoretic text, which in fact are not there.  One word is natan (נתן) when the word actually found there is v’i’taniym (וַיִּתְּנֵם); the second is the word luach (לוח), when the word there is actually lach’oth (לֻחֹת). In the first instance, it doesn’t really change the meaning of the verse. But the second one is important, as it is the plural form of the word lach (לַח) (H3892), which means fresh or unused.

So in the passage that is translated as tablets of stone we find the underlying Ivriyt to say:

עַל־שְׁנֵי לֻחֹת אֲבָנִים

This transliterates as: Al-sheniy lach’oth ebeniym, meaning upon two fresh (unused, uncut) stones.

In Exodus 34:28, do we see the Strong’s chosen word luach (לוח), or the word meaning fresh, i.e. lach’oth (לֻחֹת)? Applicable portion:

וַיִּכְתֹּב עַל־הַלֻּחֹת אֵת דִּבְרֵי

Transliteration: v’y’kathab al-ha’lach’oth eth devari. And he wrote on the fresh ones the word.

And in Exodus 24:12 we see the following:

אֶת־לֻחֹת הָאֶבֶן וְהַתּוֹרָה וְהַמִּצְוָה אֲשֶׁר כָּתַבְתִּי לְהוֹרֹתָם׃

Eth lach’oth ha’eben v’ha’torah, v’ha’mitsvoth asher cathab’oth’i l’ha’y’ratham.

The fresh stone, and the Torah, and the commandments, which writings to the binding thereof.

So, as we can see, tablets is not the word there at all! Rather it is lach’oth (fresh, or fresh ones [fem. Plural]).

Now the question becomes, which fresh stone was used to scratch this Torah, these commandments?  We return to where we started:

Shemoth (Exodus) 24:9-10
Then went up Mosheh, and Aharon, Nadav, and Aviyhu, and seventy of the elders of Yashar’el: 10 And they saw את eth the Elohai of Yashar’el: and there was under his feet as it were a paved work of a sapphire stone, and as it were the body of heaven in his clearness.